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.
Considering how powerful is the copyright mafia (Remember that the pirate bay founder got jail-time) I totally understand why the people running the instance are doing so. I get why user are pissed off, but they’re free to host their own instance and deal by themselves with the legal liability