Idea: s2s shared groups with Pub-Sub

I saw you guys talking about the difficulty is using JM shared groups across s2s nodes. Gato says we need a new JEP to handle this, which would probably be the cleanest way of doing it, but I had another idea.

Could you use Publish-Subscribe (JEP-0060) to do this? I’‘ve only skimmed over the pub-sub JEP, but it seems like with a little client support, you could add shared groups that way. In this setup you could have a JID similar to "pubsub@example.com/Accounting Department" that people from other servers could subscribe to. You could bundle presense notifications inside the pub-sub handler. You would have to deal with the fact that the user normally has to subscribe to whatever you’‘re publishing, so you’‘d need some ability on the subscriber’'s server and the client to auto-subscribe users.

This may be a bad idea, but I wanted to throw it out here. Thanks