Doesn't really matter. They will probably just add the edo-kage, sound 4 DSM Kabuto and new Tobi costume and the masses will buy it........myself included.
I will be pissed if they make as play as Sasuke when he and Itachi face DSM Kabuto. Clearly Itachi did most of the things in the battle and we should play as him. I am not a big fan of always playing as Naruto/Sasuke throughout the gameplay 99% of the time.
i believe they will restart the war arc from the beginning to what ever point they decide to stop its the safest decision as we will just get some random story to get back into the war