Hi, so it has been a while since I played the game or came into this forum so I apologize if this was answered previously.
edit? Just to clarify I mean more the characters and not organizations.
It's definite branching, so if you are with the Gorgons you don't get to interact with Kiri, Eva, and the demon hunters, and vice versa. If either is needed for a plot they get a "unique" scene that you won't see if you aren't on that branch. More importantly, both relate to the ending and both alter how the ending(s) play out.
Same with the branching on Day 5 but to a lesser degree, as there is overlapping just the conclusion to that plot is different depending on which branch you are on.
And as far as the discord discussion earlier (sorry been busy with the update), it's kind of semi-public. There is a link on the public release posts, but some stuff in there is for patrons only (certain previews and some concept stuff).