Disclosure: as a moderator of the /c/anime and /c/manga communities on ani.social, I don't want to try to influence anybody's decision regarding this as I think there is plenty of space for multiple communities to exist at the same time.
That being said, after the defederation happened and there was clear hostility from the ml admins toward much of this type of content is when I made my account on that instance and started up activity on those two communities. I agree that there is an inherent risk of these communities being purged from the ml instance and that is one of the main reasons I wanted to establish an alternative community that is well established with existing content that users can migrate easily to. Quoting myself from that post:
In any case, I think this issue validates concerns that were raised after the initial defederation happened that the ml admins could come to view any kind of lewd content or fanservice as anathema to their instance. It begs the question if the anime or manga communities on ml are on borrowed time. If the admin’s metaphorical Eye of Sauron passes over their community on a day a lewd clip, key visual, or trailer is posted, that could be it for them.
All that said, the reality is that unless you use an ml account (which you unfortunately posted with), then you can access both communities. I had primarily been using this ml account on lemmy for some time until the defederation happened, and then proceeded to make an account over on ani.social to access that content and drive activity in those communities.