I don't think it's fair to say content shouldn't be included just because someone doesn't want to see it.
It's not that I don't want to see it (honestly, I don't care, sex is sex), just that it will be Power Vacuum 2, but not in a good way (kinda like Teen Wolf 2, for those who don't know, Michael J Fox had no interest in returning, so the movie became a re-hash of the first one with a different actor playing his cousin). I don't want to start an incest/NTR debate since I know it's dumb (two different things, people), but you can't deny that incest has a lot more leeway than NTR. You can fit incest into practically anything, while NTR has a much more narrow margin. Simply put, NTR is the focus of the story, while incest can be added as an afterthought. You want to make a detective story set in a post-apocalyptic world where magic returns? Make one of the girls your sister and bam, it's incest. Face it, NTR is high maintenance while your sister is easy.
The reason why NTR works in Power Vacuum is because it's a story mechanic. I've said it before and I will say it again, Power Vacuum is NOT an NTR game, it's an anti-NTR game. The whole point is to avoid it. And that's why it drives the story forward. So if WWG can come up with another way to drive the story forward and it fits better in the new narrative, why return to NTR and limit the story?
So, to reiterate, your sister is a cheap slut. I mean, I fucked her.