Short version. Something happens at the end of Disc One in the original game, some fans "love" it some hate it so much they modded the game to change it.
Remake is announced but it will be a three part game (the first part was released.. about two years ago). The ads start to play with the idea of "something changed". Some character seems to know things they shouldn't. It all gives a big "multiple dimensions" vibe. Yet, they don't commit to any outcome, nor they explain the mess that was happening with the changes (are they actual different dimensions?)