Meta

I see what you are saying. I've changed the settings to only show my subscribed feeds by default because as you said there is a lot of random stuff.

What you are seeing with "All" on aussie.zone is "All" of the feeds that users on aussie.zone are subscribed to. If no one on aussie zone has subscribed to [email protected] then it will never show up on anyone's All while in aussie.zone. If one single user subscribes to it then it will start showing up.

So by default in "All" you will only see Meta communities if people here subscribe to them. The same will likely work the other way. Users on Meta won't see aussie.zone communities unless someone there subscribes.

That said I wouldn't put it past Meta to have "bot" accounts that subscribe to ALL communities on each instance. That sort of action would put a strain on these instances as all posts would go back to Meta. If they pulled that kind of trick then I'd be all for defederation as it would impact the performance and could indicate Meta are just scraping all content from every instance. They'd be pretty dumb to do that but I wouldn't put it past them.