I'm guessing Patreon is reacting to the changes in the legal landscape. The same ones that made Craiglist close its Personals section (or however it was called): the increased liability for the platform for whatever behaviors the public at large might find objectionable. Or find an excuse to take an issue with, really.
From what I know, the anime genre creators were a fairly popular niche (with the associated income stream), so they probably weren't taking these changes lightly.
I'd say write your congressmen (I'm not from US myself), but at this point it seems futile.
These are private companies, other competitors have stepped up that are willing to take on a certain level of risk -- no need to get the government involved. People didn't stop making video games because of "moral" activists like Jack Thompson. Anime is a global industry for Japan, much like K-Pop is for Korea; however, I'm willing to bet that far more than just anime creators (to say nothing of their respective fan bases) have been alienated by Patreon's policies. One of my favorite creators, Louis Rossmann, is pretty vocal about being against Patreon's moral policing. I don't even watch anime, but if you don't see anything wrong with Patreon's business strategy, you can at least observe how the market is reacting to it (i.e. badly enough that they need to cut some of their top senior engineers, even though their business model practically prints money in a scalable way -- a rarity in the SoftBank tech bubble -- and the industry they are in is one of the LEAST affected by the coronavirus pandemic).
From what I know, the anime genre creators were a fairly popular niche (with the associated income stream), so they probably weren't taking these changes lightly.
I'd say write your congressmen (I'm not from US myself), but at this point it seems futile.