To expand, the admin basically said "people, you need to make accounts on this instance so you don't miss reports!". The mods then didn't. The admin said "do your job or I'll have to do it to keep moderation up". The mods didn't. So the admin did some mod work, and the mods cried that they were being interfered with.

Their solution was to pack up their community and all their users and leave, and to lock the community so nobody else could use it.

And the users mostly considered themselves not the property of the moderators