All spoilers to the Danganronpa Series will be unmarked!
Sayaka's hate towards the Future Foundation comes from encounter with Maverick, under disguiseBecause that seems obvious, isn't it?
Hajime will become Izuru in an attempt to combat the despairsGiven how much he wishes he could have his own talent, and how much he wishes he could do more, Hajime may undergo the transformation into Izuru in order to help gain an edge in the fight against the despairs.
- Jossed. [[spoiler: He's already Izuru, he just doesn't know it
Izuru will be a Hajime cloneOne that will later undergo the Izuru Kamakura project. We know the despairs stole cloning plans and, because of Ryouko, we know that clones can be very different then their... shall we call it DNA sources?
Junko will try and convince some of the named anons to side with her.It's not hard to imagine given all the emotional stress they're under. Maybe they'll all hit their Despair Event Horizon at some point, then Junko will come in and try to convince them to help her. Whether or not it works may be up to their creators.
The people Monaca reanimatedAre four of the people who died during the attack on Hope's Peak. Meaning that we may see Ryouko, Nagito, Kazuichi, Hifumi, Maro, and Sakura again... just not as themselves.
- Partially confirmed. Kazuichi and Nagito return, but the other two to come back from the dead are Celestia Ludenberg and Natsumi Kuzuryuu.
- Ryouko as well.
Four Ressurections and One CloneRyouko, Nagito, Kazuichi, and Celeste are the people who Monaca ressurected, as she makes mention of ressurecting 4 people, not five. Natsumi is likely a clone with fake memories implanted.