And other fanworks, for that matter, but let’s talk about fic: When AO3 was proposed, it was in response to Strikethrough and other similar events. Livejournal deleted a lot of accounts without bothering to distinguish between actual pedophiles, survivor support groups, and 100% consensual fantasy fandom activities being done by adults with other adults (most of which involved RP accounts for 16-year-old Harry Potter characters anyway).
I helped write the first AO3 Terms of Service and set up the Abuse committee. AO3 was always intended to be welcoming to all kinds of fic, no matter how dirty, sick, socially unacceptable, bizarre, or out of fashion. During those initial TOS talks, we specifically discussed grotesque RPF snuff porn as the test case for something all of us on the committee found distasteful but would nonetheless defend because, by defending it, we created a space where all of our own favorite things were protected too.
Policing fic content is a slippery slope. Even if you only police the “worst” stuff, you create an environment where the more sensitive authors and no few of the ones “shipping to cope” are no longer comfortable posting at all. Attacking people for posting fic about rape/abuse/etc. is demanding that all survivors disclose. No amount of whining and backtracking will change this fact. It is a disgusting behavior that drives people from your fandoms and creates needless misery while adding nothing of value to the community.
If you want to kick certain kinds of content off of AO3, you do not belong on AO3 in the first place.