Nobody has said these are non-canon scenes, only that Grace may be slightly embellishing these stories or just flat-out making them up. If so, she must have a good reason for it, and if you want to see a reasonable theory for why she's doing it, see my earlier post:
I think they have every right to be angry at what's happening in this thread, from the constant whining about Grace having had a (possibly) adventurous sex life that people have the option to see or not see, to that one person who keeps coming here making falsehoods about the previous game and falsely asserting this game will have certain content that it will not have.
Actual discussion about the game and its story, like what path might Mia and the MC have to rekindle their relationship, what's in those letters Mia is receiving, what's the history between Grace and Sebastien, will Emma make a re-appearance, how will Grace be able to save her bar, etc, are all being overshadowed by non-controversies and people spamming the thread with falsehoods.
We all seriously need to move past these discussions about Grace and the lies about Mia's character and actually talk about the substance of the game itself.