Explain.
I agree that would be nice. Hopefully it is something that will eventually get added as a possibility, but I don’t know enough about the background workings to say if it is being considered or not.
If I understand the fediverse correctly, if the instance dies (meaning all the background servers are taken away), everything on that instance is gone; accounts, communities, posts, comments. Since the instance is the host, they are the ones holding the data; if they decide to stop, it’s gone.
However, the creator of the community and its members could create new accounts on another instance to rebuild the community.
My list of blocked porn communities is more than double my list of subscribed communities; reblocking would be the biggest pill.