Fair point honestly. I'd always seen the ending of DR2 as being more about them having always been redeemable, but I can see where you're coming from, and that fits in nicely with characters like Fuyuhiko and Mahiru who did terrible stuff before even becoming despair and Fuyuhikos entire arc is about him continuing on despite that.I didn't really count Izuru, but yes, so far she's had an individual process. The thing is that a lot of these reactions are driven by what the anime's leading us to believe will happen. Aside from Hajime and Mikan, none of the DR2 cast have mentally changed at all since the beginning (even Fuyuhiko, whose sister was killed), and we only have 3 more episodes to operate with.
But the method behind the DR2 cast's despair is very important; as important as the end result. If what they suffered was "forced brainwashing against their will," they will be made redeemable characters. Characters who weren't in control of their own actions. This fundamentally changes the message of DR2's ending and how they decided that they would still exit the VR simulation, facing whatever future awaited them despite who they actually were.
Honestly though I'm still super excited to see the DR2 cast post-graduation. The ending to 2 implies that they're reformed, but it also implied that they were still fucked up in some major ways if Byakuyas concerns aren't taken lightly.