Some hints from Shippuden. This thread is just a sequel to the last one, that had hints towards the reveal for Itachi and the Uchiha clan/Konoha from part one:
Hint 1
^Itachi smiles when he notices how much Naruto has improved in terms of power.
Hint 2
^Itachi was reluctant to relay any important information about Naruto to Sasori.
Hint 3
"Perhaps you'll let me beat your target half to death, too?"-Kisame
"Don't get cocky, Kisame."-Itachi
"I'd like to find him (Naruto) quickly so I can rest."-Kisame
"There's no rush, so go ahead and take a break. We still have plenty of time."-Itachi
He doesn't like the idea of Kisame capturing Naruto. (For obvious reasons, given that he does not want him to be captured period.) He gives excuses so that they don't go after him and Kisame does not get suspicious.
Hint 4
If you're wondering why I just included these two pages, it's just because it's abnormal for one to go to an organization of their own accord and not participate in discussions. Itachi's just the "..." guy here. He doesn't seem to enjoy their discussion at all, nor take interest in it.
Regardless, it's also nice to see that after every time Sasuke is mentioned or Orochimaru, a panel with Itachi silently listening is shown. Later on, we found out that he worried about Sasuke, and even wanted to get rid of the CM Orochimaru placed on him.
Also, later on Kisame's statement contains great irony.
"Heh...impressive. You must be proud of your little brother, Itachi-san."
Yes, he is very proud.
Hint 5
In a later conversation the Akatsuki are having, Itachi remains looking uninterested. Until, Deidara mentions wanting to kill Sasuke. Itachi immediately begins looking directly at him. For supposedly not caring about Sasuke's, this caught his attention.
Even Kisame notices and decides to ask him:
He doesn't answer. He just continues having a stoic expression on his face. However, it's not as stoic as before and actually looks a little worried to a point. Probably because he is.
Hint 6
Hint 7
Itachi just walked out into the rain. Kisame states that it looks like he's crying. (He really was.) He just went into the rain to make it look as if he wasn't.
Though, after a moment of mourning, he says that he knows Sasuke didn't die (he knows Sasuke has resolve and he gave him a goal... he has faith that he didn't die to Deidara) and mentions that the storm passed.
A person who truly despised his brother would not have faith in the latter's power. At least not in a manner like this.
Hint 8
^Him just wanting to talk with Naruto and having absolutely no desire to capture him even though the organization he joined requires him to do so.
Hint 9
"What is it about my brother that makes you care about him so much?"-Itachi
^Why would Itachi ask this if he supposedly does not care for his brother? Why ask why someone else cares for someone he is supposed to not care for himself? Why the curiosity?
"Because I'm a better brother to him than you ever were."-Naruto
Notice Itachi's reaction to Naruto's words:
He smiled. He was glad to hear that Naruto viewed Sasuke as a brother and viewed himself as a brotherly figure for Sasuke. It reassured him that Sasuke would be fine after his death.
Hint 10
Just wants to talk to him. Gives Naruto the crow. Naruto asks "why?". Itachi just leaves and says that he has something he needs to do. Still doesn't try to capture him.
Hint 11
^His view on reality is a hint.
He is just saying what is common sense here. Humans only know and accept what they're aware of and grew up to think of as right and wrong. However, even so... there's a chance that a person can be wrong in what they think, if they don't know all the facts.
This can pretty much fit in with nearly anything in this manga and out of it. However, in this case it can directly correlate to the "truth" Sasuke knew prior to the one Tobi told him.
Hint 12
The guy took several moments throughout his fight with Sasuke to acknowledge how powerful he had become.
We find out after the fight that the entire aim was to benefit Sasuke and see how powerful he'd become.
Hint 13
"You finally show yourself."- Itachi
The premise of this fight on Itachi's behalf prior to the truth reveal was for him to supposedly want to kill Sasuke, take his eyes, and acquire EMS. That's all he needs to do.
The problem here is that the word "finally" denotes that Itachi wanted Orochimaru to emerge from Sasuke. If Itachi's true goal were to actually attain EMS, he wouldn't need to push Sasuke to the point of releasing Orochimaru. He would just kill Sasuke at an earlier point and be done with it. Take his eyes, and get EMS if that were his true aim.
Hint 14
Itachi smiles and says something. We cannot know what it is yet, which is why the kanji are "Illegible" in the speech bubble for him.
It's an obvious parallel to the forehead tap gesture he'd give Sasuke when they were younger. Brotherly love.
Hint 15
^Zetsu was in disbelief.
And then of course when Zetsu goes to report to Tobi:
"It's just as I predicted."-Tobi
And, that's the last hint before the truth for Itachi is revealed.
tl;dr- There were plenty of hints in both Part one and Shippuden for the reveal. There's no chance of it being a retcon. It was planned in a decent manner.
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Hint 1
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^Itachi smiles when he notices how much Naruto has improved in terms of power.
Hint 2
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^Itachi was reluctant to relay any important information about Naruto to Sasori.
Hint 3
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"Perhaps you'll let me beat your target half to death, too?"-Kisame
"Don't get cocky, Kisame."-Itachi
"I'd like to find him (Naruto) quickly so I can rest."-Kisame
"There's no rush, so go ahead and take a break. We still have plenty of time."-Itachi
He doesn't like the idea of Kisame capturing Naruto. (For obvious reasons, given that he does not want him to be captured period.) He gives excuses so that they don't go after him and Kisame does not get suspicious.
Hint 4
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If you're wondering why I just included these two pages, it's just because it's abnormal for one to go to an organization of their own accord and not participate in discussions. Itachi's just the "..." guy here. He doesn't seem to enjoy their discussion at all, nor take interest in it.
Regardless, it's also nice to see that after every time Sasuke is mentioned or Orochimaru, a panel with Itachi silently listening is shown. Later on, we found out that he worried about Sasuke, and even wanted to get rid of the CM Orochimaru placed on him.
Also, later on Kisame's statement contains great irony.
"Heh...impressive. You must be proud of your little brother, Itachi-san."
Yes, he is very proud.
Hint 5
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In a later conversation the Akatsuki are having, Itachi remains looking uninterested. Until, Deidara mentions wanting to kill Sasuke. Itachi immediately begins looking directly at him. For supposedly not caring about Sasuke's, this caught his attention.
Even Kisame notices and decides to ask him:
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He doesn't answer. He just continues having a stoic expression on his face. However, it's not as stoic as before and actually looks a little worried to a point. Probably because he is.
Hint 6
At another meeting post-Deidara's death:
^Look at Itachi's stoic expression when hearing Deidara lost to Sasuke.
Okay, now look at it on the following page when he hears that Sasuke apparently died:
The look of sadness on his face is apparent. He couldn't keep his stoic expression any longer.
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^Look at Itachi's stoic expression when hearing Deidara lost to Sasuke.
Okay, now look at it on the following page when he hears that Sasuke apparently died:
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The look of sadness on his face is apparent. He couldn't keep his stoic expression any longer.
Hint 7
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Itachi just walked out into the rain. Kisame states that it looks like he's crying. (He really was.) He just went into the rain to make it look as if he wasn't.
Though, after a moment of mourning, he says that he knows Sasuke didn't die (he knows Sasuke has resolve and he gave him a goal... he has faith that he didn't die to Deidara) and mentions that the storm passed.
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A person who truly despised his brother would not have faith in the latter's power. At least not in a manner like this.
Hint 8
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^Him just wanting to talk with Naruto and having absolutely no desire to capture him even though the organization he joined requires him to do so.
Hint 9
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"What is it about my brother that makes you care about him so much?"-Itachi
^Why would Itachi ask this if he supposedly does not care for his brother? Why ask why someone else cares for someone he is supposed to not care for himself? Why the curiosity?
"Because I'm a better brother to him than you ever were."-Naruto
Notice Itachi's reaction to Naruto's words:
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He smiled. He was glad to hear that Naruto viewed Sasuke as a brother and viewed himself as a brotherly figure for Sasuke. It reassured him that Sasuke would be fine after his death.
Hint 10
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Just wants to talk to him. Gives Naruto the crow. Naruto asks "why?". Itachi just leaves and says that he has something he needs to do. Still doesn't try to capture him.
Hint 11
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^His view on reality is a hint.
He is just saying what is common sense here. Humans only know and accept what they're aware of and grew up to think of as right and wrong. However, even so... there's a chance that a person can be wrong in what they think, if they don't know all the facts.
This can pretty much fit in with nearly anything in this manga and out of it. However, in this case it can directly correlate to the "truth" Sasuke knew prior to the one Tobi told him.
Hint 12
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The guy took several moments throughout his fight with Sasuke to acknowledge how powerful he had become.
We find out after the fight that the entire aim was to benefit Sasuke and see how powerful he'd become.
Hint 13
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"You finally show yourself."- Itachi
The premise of this fight on Itachi's behalf prior to the truth reveal was for him to supposedly want to kill Sasuke, take his eyes, and acquire EMS. That's all he needs to do.
The problem here is that the word "finally" denotes that Itachi wanted Orochimaru to emerge from Sasuke. If Itachi's true goal were to actually attain EMS, he wouldn't need to push Sasuke to the point of releasing Orochimaru. He would just kill Sasuke at an earlier point and be done with it. Take his eyes, and get EMS if that were his true aim.
Hint 14
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Itachi smiles and says something. We cannot know what it is yet, which is why the kanji are "Illegible" in the speech bubble for him.
It's an obvious parallel to the forehead tap gesture he'd give Sasuke when they were younger. Brotherly love.
Hint 15
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^Zetsu was in disbelief.
And then of course when Zetsu goes to report to Tobi:
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"It's just as I predicted."-Tobi
And, that's the last hint before the truth for Itachi is revealed.
tl;dr- There were plenty of hints in both Part one and Shippuden for the reveal. There's no chance of it being a retcon. It was planned in a decent manner.