I don’t know what that is, but it feels to me like it might be a fork bomb.

Edit: Yep, fork bomb.

I got the impression that it wasn’t exactly unprompted and that they had been being overwhelmed with take down requests. Like it or not, Lemmy instances do have to follow the laws of their local jurisdiction. Which means responding to take down requests when applicable. The post suggested that until they had tools to better manage that, they had to block them, but have unblocked them now which implies that they have those tools.

I think they just ublocked the dbzero. Or at least I saw a post about it recently saying they’ve unblocked the piracy communities. I assume that’s what you’re referring to.