No, setting up a personal instance isn’t a solution for the potential problem I’m describing here.
I’m not discussing whether an instance owner or commercial platform is at right to shut down an instance (an instance administrator probably is in most if not all countries), but the risk of a loss of continuity and the seemingly absence AFAIK of a continuity mechanism in the design of the Lemmy platform.
As explained: it’s possible to migrate a Mastodon account from one instance to another including followers.
Is it also possible for a moderator of a community to move a community from one instance to another including all subscribers? That would be a solution. Setting up one’s own instance isn’t beside keeping your account. But that’s not the issue.