You sure about that? Every single one of his older games (except the short assdiction) had NTR in some form. "Corrupting Jennifer" and "black and white photoshoot" were full blown NTR. The only reason he stopped working on Jennifer was because the Mia games were his main project and couldn't with the work load. Mia also had plenty of NTR. Let's not pretend like Inceton was some vanilla messiah that's betraying his followers with one bonus scene.
I should have been more clear, I was mainly referring to this title, and Mia in reference to supporters. Also, it's actually two bonus scenes.
With that in mind, "let's not pretend" like all of season 1, and all of season 2 up until recently had any semblance of any ntr-ish type of stuff going on. Season 1 of Mia already had that stuff going on midway into its development, and you got countless people talking about that.
Is he betraying his followers? Maybe, maybe not, I'm not going to debate that, it's entirely based on ones perspective. However, I am willing to bet though, that most of his patrons are not in it for the ntr stuff.
I will also wager that most of his patrons came from playing this title, and early versions of Mia where the ntr stuff wasn't fully prevalent yet. Show me a dev here that is making a killing, money wise, with straight up ntr content. Let's not kid ourselves, we all know that this specific fetish isn't widely popular. Another bet that I am willing to make is that his patreon numbers are due largely in part to one main fetish...incest.
If a majority his patrons are so fond of his ntr content, then why not incorporate it heavily into this novel/game, of which, seems to be his most popular title? That's his thing right? That's his fanbase right? I'll just answer the question myself, it's because he doesn't want to lose money. It's not what got him his main following in the first place.