I have been away from social networks and Mastodon for some weeks, which is awesomely good for my mental health, so I have no idea what the fuss about #fosstodon is.
What I know is that deciding to block a historical instance because one of their mods misbehaved is a #ShitMove™.
Instance blocking is good for shitholes like Gab or truth.social.
Blocking thousands of people without trying to fix issues is the best way to ensure that ActivityPub doesn't work in the long run.