the game specifically says it isn't "The main game contains avoidable, non-canonical NTR content", I don't know how people can read it differently.
it is a fun novel, and I hope you will continue to enjoy it.
Yeah but if you play the game it still has themes of competition and a looming spectre of potential betrayal like with Lucia in the cabin. So the MC isn't literally cucked in any canonical content, but it might still rub people the wrong way who don't like NTR because they don't want those themes in the game period.
I mean personally, while some people were mad at Femdom Ophelia, I was actually mad prior to that with the way Ophelia basically makes the MC walk on eggshells but then gets Catherine to help her with lactation when we all know how bad Catherine is with boundaries.
I actually appreciate in chapter 10 when Ophelia realizes that after being pounced on by Brenna, that maybe she could have been more lenient with MC. Of course what he did to her was bad. But it was just annoying seeing her basically make him walk on eggshells in a way others didn't have to.
Personally, it feels like the same kind of betrayal as NTR to have a woman make you jump through hoops and gaslight you into thinking you're a creep wanting to do a given sex act that she then begs another guy to do. Hence why in many NTR stories, to twist the knife they don't just have the woman say she loves the rival, they also have her say she's doing a thing with him that she'd never let her husband do (anal is the typical example but not always).
And I'm not even against an NTR game. I'm fine with it as long as I can see myself as the bull not the cuck.
So when you say "I don't know how people can read it differently." People are worried, that the game will be written in a way that the canon segments will still be tainted by the themes of betrayal and competition that make the NTR in the non-canon even an option.
And before you assume I'm some hater, I've been supporting the dev on patreon for several months by now, even while he has postponed the update.