Ok, first off I'm not saying this is what I think is happening, this is more of a "this is possible" kind of theories just for something to think about.
So we are all assuming that Kabuto hasn't ended Itachi's edo or summoned his coffin because he can't either because: if he does it will end edo madara and muu at the same time or the kotoa that the crow layered on Itachi has somehow deactivated the ability to summon his coffin (this also assumes that the summoning coffin is linked to the talisman charm and not the edo tensei itself).
BUT, what if Kabuto can summon Itachi's coffin or end just his edo and the only reason he hasn't is because he wanted to see what Itachi did or he thought Itachi would lead him to Sasuke somehow.
If this is the case then it would allow Sasuke to get all pissed off again and be the guy who fights Naruto at the end battle of the manga instead of being the born again christian dr. snakes character he has become all of a sudden.
So we are all assuming that Kabuto hasn't ended Itachi's edo or summoned his coffin because he can't either because: if he does it will end edo madara and muu at the same time or the kotoa that the crow layered on Itachi has somehow deactivated the ability to summon his coffin (this also assumes that the summoning coffin is linked to the talisman charm and not the edo tensei itself).
BUT, what if Kabuto can summon Itachi's coffin or end just his edo and the only reason he hasn't is because he wanted to see what Itachi did or he thought Itachi would lead him to Sasuke somehow.
If this is the case then it would allow Sasuke to get all pissed off again and be the guy who fights Naruto at the end battle of the manga instead of being the born again christian dr. snakes character he has become all of a sudden.