This is one of the things that really confuses me about Patreon's rules, and the rules concerning depictions of incest in porn generally. Patreon is a US-based company, as are many of the porn studios that trade in 'stepcest' content that has proliferated in the industry in the last 5-10 years. Their concerns are therefore over enforcement of US laws regarding this type of content....... but letter-of-the-law, there are a very many jurisdictions in the US where 'stepcest' is also statutorily prohibited as if it was bloodline-incest. So it seems like it's more of an appearances policy than an actual legit legal concern.
Quite correct.
And just to add to the confusion, other games (like Girl Gone Bad for example) feature actual incest but manage to get away with it without patreon threatening to pull the plug.
But the Twist is one of those games that is subject to patreon scrutiny and presumably it will continue to be like that so long as KST is making money from it.