I do not like kinetics in general, because they are not games, but movies. While they might have a good story, they do not fulfill the want for game play. Actually, few vn do that, but kinetics even less so.
What you cite is not plans for ntr, it is the dev speculating that such things might be included, if interesting scenes came up.
I actually do not get the hate for ntr. Like really, just look at the comments of people hating on "ntr". And the quotes are necessary, because they call stuff ntr, that ain't.
You need cheating for ntr. Or at least humiliation in a threesome. Not merely spying on a potential love interest. Or I believe in this game it was a flashback to a time when they were not even a couple. Now, if she would use that flashback to humiliate him, and praise how good her past lover was, that might spill over into ntr.
Imho a bad ending in a vn as an ntr route would acutally be rather clever. Just skipping content does not give the satisfaction of having avoided the content due to your ingame actions.