As as I said just below, I didn’t mean to have every community on that instance.
Just to have a single Fediverse community on one instance that could be used by everyone. You wouldn’t have user registration on that instance, and as such it would not have to replicate any of the other communities except the local !fediverse one.
People shut down / buy out that server? The community falls back on !fediverse or !fediverse while we figure out how to deal with the situation.
It’s kind of similar to what people are trying to achieve with lemmy.film: a single instance on one topic, federated with as much instances as possible. To get discussions in one active place rather than scattered across dozens of communities.