I just think, that excluding specific people that have not actually done anything wrong yet(at least on this platform) will lead to a homogeneous userbase. And even if he is not obliged to host anyone, I think it would be a way smarter decision if someone, who is aware of their danger, is hosting them. That person could later moderate their usage of their accounts, if they overstep certain limits way sooner than someone hosting them on another instance.
Seems interesting, I’ll definitely try that one out