I'm not talking about this game, I know NTR will be avoidable, Dev clarified it.
But in general:
In my experience sometimes when Devs said it's avoidable they meant it's skippable, where it happens and you just don't see it, not everybody knows the difference between preventable and skippable.
Also there was a funny case when Dev said NTR is optional and then made a scene where MC's girlfriend kisses (when MC is not around) some dude, not on a cheek but a real passionate french kiss.. When players called him out on this BS he said he thought it's not NTR

(well technically it wasn't I guess)