The issue was "sexually abusive content" and fictional rape. There's a decent amount of it already on Patreon already - I checked first before I set my own page up to ensure that there was already an establishment of it - but their stance seems to be fairly laissez faire for the most part, and I think they only do something like this when a page is reported - which mine was, because of that one asshole on a mission.

I can see where Patreon are coming from though; the moral panic being whipped up by SJWs in the last 2 years is oriented around pressuring companies and networks that host the content they find offensive, and doxxing content creators that they don't like. Being seen by the public and the far left media as a haven for deviant content is not good for their image, as they would be labelled rape/murder/pedo "enablers".

All things considered, they were pretty good about it.