No just free association. But having no alternatives to legitimate needs, like participating in our civilization’s free speech discourse through the internet, free association doesn’t help. So before the fediverse you were “forced” to associate with reddit/facebook/twitter or have little association at all.

I’m not sure how anarchism would work for a social media platform. Everyone is a mod? Everyone can post anything and can delete anything? 😀

I believe generally as a philosophy anarchism only makes sense as all authority should be challenged and needs to be justified or be abolished. The amount of authority justified and needed might be relative to the level of “enlightenment” of the participants.