Yeah that’s essentially the system I was thinking of but more something the communities could opt into with each other, and could easily moderate how much and what “meta” content made its way into their community.
Big communities would probably just share common posts between each other like they might use a mega thread for, small communities might pull more “meta” content to keep activity up. But making it all an opt in kind of thing on the community level.
The main reason I think it needs to be a core part of the software is just buy in. Like, whatever the solution to this thing that apparently a lot of people think is something or an issue, it needs to be pretty well supported by everyone. Like, apps, instance admins, mods, they kinda all need to be on board - and that probably means something coming to the closest thing this whole mess has to a top.