Not really understand the point you are trying to make. This post is about communities on dead instances. Dead as in the host has stopped hosting it. Those communities will not ever federate again. So if you post in such a community from your own instance, it will not federate to other servers. It also causes issues with moderation.

Most of the communities on those dead instances have moved to other instances. And people should use those instead of trying to use the dead instance community.