This seems majorly flawed. If lemmy.world went down we would then loose a lot information/posts.
Shouldn’t there be a timeout period of some sort, or a way to open a new community of the same name on another instance? Maybe even a backup instance? So say for example
A community on lemmy.ml is created. Let’s call it awesome-community. The moderators of awesome-community set backup of awesome-community to lemmy.world awesome-community. Then all instances on fediverse will see that information and if a user tries to view awesome-community lemmy.ml and it says offline then it redirects to awesome-community on lemmy.world.
I think having redirects for offline communities would be great. Even if you could set a timeout feature so say after 24hrs offline redirect. If not been 24hrs then just show it’s offline.