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.
People speaking out and getting mad is natural and helpful. It’s how discourse works at this scale. Maybe the mods change their actions or maybe they don’t, but saying nothing about bad things happening won’t help anyone and getting mad that others are saying things is stupid.