So apparently Valve sent notices to various developers that they will be removing their games because of pornographic content unless it's removed (including Huniepot's game Huniepop). But I saw one developer comment that their Steam version of a game was targeted even though it doesn't contain or advertise any nudity (the 18+ version can only be purchased off of Steam).
Sounds like people are mass-flagging games or something. Either that or Valve just really wants these games off their service.
No safe harbor for weebs.