I'll try this one more time.
Tsunade said she was the only person that knew the jutsu.
Unless Kishi recaps, Sakura cannot know it. Period.
This leaves Wood Release, Sage Mode, or something different.
Your time might be better spent with Hooked on Phonics than bashing Sakura.
Perhaps she's been taught the jutsu theory and is yet to fully master it - maybe this will be the first time she'll be using it, the first time the chakra is fully stored etc. Could be a display of her intelligence if she can pull it off the first time, having only the theory down.
Just an idea...
I'll try this one more time...
Wood Release is a Kekkei Genkai.
She's about as likely to possess this blood limit as she is the Sharingan.
Should remember;
1. Sakura's parents aren't shinobi, they are civilians - so it's unlikely.
2. Wood Release requires the duel affinity for Water Release and Earth Release - both of which Sakura hasn't ever shown in the anime/manga.
3. Tsunade absolutely does not possess Wood Release - nor has any other Senju except Hashirama Senju. The only ones who do are those who have altered their DNA using cells from Hashirama (ex: Madara Uchiha & Danzō Shimura)
Sage Mode
There's a few major issues with this 'theory'...
a) Sakura doesn't have a ridiculous amount of chakra required, nor the years/clones to spend training on it.
b) She has no contract with Toads or Snakes.
c) Only Hashirama mastered Moukton Senjutsu and that's because he has Wood Release, he is also the only one to ever achieve this. Tsunade does
not have Wood Release, nor is she a Sage like her grandfather - this is not something she's capable of teaching Sakura.
In all honesty, if anyone else was going to pull Sage Mode out their ass - it would be Sasuke, not Sakura. Not that I think he will, Kabuto has taken care of that - but Sasuke certainly more capable than she would be.
I'm not Sakura's biggest fan - but I do hope she gets some form of 'redemption' as some have called it.
I'd like to see her hold her own at least and not be a failure/liability and muck things up. To not require saving and to most importantly NOT CRY.
That being said - if it comes on too strong, her power/improvements... then it'll feel vastly unrealistic. But I have faith, I think Kishi did a good job with Hinata and her Clan so I figure he'll pull it off for Sakura too.
There's a lot of emphasis from Sakura about Tsunade - so Tsunade based techniques, perhaps ones she's improved upon herself just as Naruto and Sasuke have improved Rasengen and Chidori...
That seems more likely to me. It's inkeeping with comments made by others on how she'll one day surpass her sensei, just as Naruto and Sasuke have their's.
