Shishui fell into a river not exactly confirmation of death. he could of easily survived that drop more believable then the crap others are throwing around.
kishi likes repeating shit xD im not saying im 100% on it being him but he has connections to naruto and sasuke thru itachi. hes perfect for tnju know itll happen lol
There is 0% chance of it being Shisui given that the Uchiha Police Force mentioned that they found his body in the river, retrieved it, and noticed it had no eyes. Then, proceeded with investigations immediately.
Nor does it remotely share the same chance as Obito's scenario, given that Kishimoto had leeway with him- Minato/Kakashi/Rin never bothered to look further into his death or retrieve the body.
There's also no way to give Shisui such a motivation. Obito's made sense since he held Rin the most dear to him. Shisui was the one who jumped off a cliff and left a political mess in the hands of his 13 yr old best friend, accepting that Itachi would likely suffer somewhat. Itachi and Shisui can handle each other dying and are accepting of the fact that shinobi do die.
Also, it is a new guy, given the dialogue.
ot: It is obvious that Kabuto is not the new Akatsuki or bad at all.