I felt that way about how the ending of the anime feels like a retcon of the ending of DR2. That heavily implied that most or all of the cast were horribly mutilated or otherwise fucked up due to their time serving Junko and that's pretty much tossed straight out the window for the sake of giving the story a happier ending.

Like, I don't mind the happy-ish ending per se, I just wish it was better justified. As-is, it feels like the writers just ignored what had come before, which felt cheap.

Otherwise, I was so-so on the "future" arc, but I thought the prequel story was actually pretty good and did a lot to make me like the DR2 crew more. Although I wish they hadn't so explicitly explained how the Most Tragic Event happened, since I preferred that having some mystery to it.