This has happened once before and they reversed it. But they said this last time too:
The discussions that have happened in various threads on Lemmy make it very clear that removing the communites before we announced our intent to remove them is not the level of transparency the community expects, and that as stewards of this community we need to be extremely transparent before we do this again in the future as well as make sure that we get feedback around what the planned changes are, because lemmy.world is yours as much as it is ours.
The Lemmy instance doesn’t actually host pirated content, does it? It’s just information about pirated content and where to find it, right? Who the fuck cares about this
Links to pirated content have been deemed illegal in various jurisdictions. That said, the piracy community on Lemmy doesn’t seem to do much more than complain about DRM, so I guess the risk shouldn’t be that high?
Still, the best way to avoid annoying letters from lawyers is to avoid risky communities. Hosting anything related to piracy, gambling, porn, or crime is just a pain, even more so than hosting normal stuff.