None of the Mod posts regarding the Blackout mentioned Lemmy as far as I‘m aware

Rumor has it they banned a lot of mods and communities for encouraging exactly that to their subscribers, so it was considered quite risky.

My presumption was that with over 200 instances, maybe over 1000 in the near future, all the old data should be collectable in theory without loss. But you’re right, there’s no guarantee of this.

Oh lawd, I bet there will be a dozen instances for different political inclinations that all have each other blocked lmao

All the users and communities registered there will cease being able to connect to the rest of the network, but the data should still be cached on all the other servers.

Do as you please. It’s not like Reddit had any etiquette for crossposting, except for subreddit-specific rules.