The moderators organizing the protest had been trying to organize their own thing for a while to port their communities over.

It's becoming increasingly obvious that the "own thing" was untenable; too many differences to reconcile. Different mod teams had given up on the process and have already started to make places on Lemmy/Kbin.

Remaining closed is seemingly impossible; if you remain closed, Reddit will replace you within 24 hours). That's not a bluff; Reddit has done it (and is creating more and more powermods in the process as these big subreddits get centralized into the hands of giant powermods that cooperate with the admins).

With that in mind, they've decided the best way to damage Reddit is from within Reddit itself. Over the last couple days they've been putting together guidance on how to stay within the letter of Reddit's rules while maintaining the protest. Among that guidance is tips to make Reddit as miserable as possible while heavily promoting alternative communities. Everything is officially following Reddit's rules to the letter, so if the admins punish these communities they're proving those rules to be a farce.

A lot of places are now making the jump to alternate communities. Some are on the fediverse (here's a list), some aren't. But now it's "official" guidance from the protest leaders, so expect to see a lot more advertising for Lemmy/Kbin from subreddits that participated in the protest.