We can’t stop sovereign countries from banning services. We can however have external Fediverse services not comply with cutting off access to users from those sovereign countries, leaving it up them to ensure their citizens don’t have access. Since we’re not making off of doing business in those countries we can ignore non-legal requests instead of voluntarily complying. Then some of the more technical people in such places could use the existing tools for blocking circumvention in order to access the Fediverse if they really want to.