Just a quick update, lemmy.world has posted an update that explains their decision here: https://lemmy.dbzer0.com/post/16795373
TLDR is that the person who removed the community is fairly new to the mod team and didn't realize there was a bit of a history to this situation. Also, looks like they are sticking with the decision this time around though.
Please don't harass the lemmy.world admins/mods though - if you don't like the situation you are free to register here or on another instance. And if you aren't a lemmy.world user, then this doesn't affect you at all.
I'm proud of our community here, and it's their loss, not ours!