Websites are cracking down hard on a lot of adult content specifically in the ENF/ABDL/similar areas. Just today Pinterest started removing pins that I had saved from awhile ago. Patreon recently did a mass banning of almost all abdl and enf creators. Especially artists. Some managed to get away untouched but many have had their main source of income wiped clean. DeviantArt while lenient is still taking down content without warning. If you have content that you like from these websites and companies, ensure you have a backup. Also depending where you live, legislation is now banning but also tracking a lot of adult websites like pornhub. So many are now requiring ID. Which removes the anonymity from browsing adult content. Likely with the increase of AI use for mass searching items, you may see things that were never flagged before now wiped clean. Many are putting tools into place to detect community guideline violations and have no human on the other side to verify if they are even accurate. Also I recently made an announcement on my DeviantArt account that I was sort of stepping away from the ENF content. Not gonna lie the cracking down on adult content has been a factor of that. Though I will still be contributing such content to CHYOA.
Banning ABDL I can vaguely understand, even if I disagree with it. A lot of people are super sensitive to anything that might even remotely in the same ballpark as pedophilia. Age play too: a lot of people don't understand or refuse to acknowledge the difference between reality and fiction. But banning ENF is just plain weird.
The issue is rather that the laws of many countries don't care whether it is real or fiction. However, the other issues are more likely a result of MC policy than of legal nature. In ENP, characters might be depicted in a way that intends to add another layer of humiliation. In some cases, that might make them look underage. This happens in written content but might be even more of a problem in visual depictions. As embarrassment and humiliation seem to be the main fetishes of ENP, there seems to be not so much content involving sexual contact between characters. That might make it easier for authors and artists to justify depicting characters who are or appear underage. (Writing seems to have quite a lot of content that falls into that category.)
People who insist on publishing erotica that has kids, often find weird ways to skirt the rules. There was someone on Chyoa a while back who had multiple threads where they were asking why wasn't it OK to just declare that the characters are "suitable age depending on where the reader is" and call it a day. They categorically refused to accept that the site says "18+ characters only" and moreso refused to label or in any way declare that the characters they write about are 18+ years old. They went asking again and again for any loopholes to avoid giving ages and based on what I saw of their writing, were very obviously implying that characters were children. At some point, this rules skirting and "teehee, look I'm not saying it, I'm only implying it in subtext" becomes creepier than outright admitting what type of fiction you want to write. Much like someone who wanted to write a rape fic and then asked if it is OK, to write about "consensual" (quotes included) story where it is obvious that the sex is rape but the writer peppers every other word with quotes to get plausible deniability, would be OK here. I think this was when non-con was hidden from new users and visitors. Sure, fiction is fiction, but sites also have the right to have their own rules if you insist on writing on site X, you should not be upset when they decide to uphold the rules and creeps are creepy.
The common meaning is "embarrassed naked female," a genre of story where the primary action generally involves a woman who ends up losing her clothes and being put in humiliating situations. ENM is the male equivalent. EUF is the underclothes equivalent. And ENP is the gender-unspecified equivalent. As for why it's being cracked down on, that's very hard for me to say. The reason gene.sis provided is as good as I can guess.
