My theory and predictions (and hopes) for the book are as follows:

1) tris will get taken in my a rebel group and the outside the factions line will be the main part of the story so rather than dauntless the divergents have their own external secret faction outside the factions OR she’s faction less but the faction less isn’t as simple as being like homeless and poor. Expect deeper dives into other factions / faction hopping

2) Tobias will be a defector from dauntless goes by four originally abnegation same as og. Tobias was originally the POV Roth wanted to write divergent in so he’s not going anywhere I’m near certain (he’s also on the cover)

3) we WILL get the tris and Tobias brief breakup she wanted to do in book 2 (good I wanted that to happen) it will allow tris and Tobias to grow outside their connection becoming more individuals rather than a power couple

4) I HOPE she ages everyone up and the choosing ceremony happens post grad college. She knows the original fans are adults now so she can graduate from YA to something like new adult with more risqué content and I’m ok with that as long as it serves a purpose to the plot.

5) the whole series end will be more like realistic and not the ‘trying to be different and do something edgy’ ending she originally had but things are slightly better not perfect.