It most certainly does violate their terms of service: the main terms require you to have copyright permission & any other rights for everything you post and there’s an entire policy specifically banning non-consensual content:

https://help.twitter.com/en/rules-and-policies/intimate-medi...

This page goes back to 2018, too, so it’s hardly new: https://web.archive.org/web/20180103200035/https://help.twit...

> Sharing explicit sexual images or videos of someone online without their consent is a violation of their privacy and one of the most serious violations of the Twitter Rules. In addition to posing serious safety and security risks, it may also result in physical, emotional, and financial hardship for the person whose media is shared.