You cannot publish a system catalog. But a user-created table in information_schema is not a system catalog.
Replication of information_schema tables works. However, pg_dump doesn't include information_schema tables into CREATE PUBLICATION command (user-defined information_schema tables aren't included in pg_dump even *before* logical replication). IMO allow publish/subscribe of tables into information_schema is harmless (they aren't special tables like catalogs). Also, how many people would create real tables into information_schema? Almost zero. Let's leave it alone. Since pg_dump doesn't document that information_schema isn't dumped, I think we shouldn't document this for logical replication.
