Do they get adopted by other instances? Are they still accessible from other instances? Can you still post on them from another instance?
Edit: From my understanding every instance that deals with a community has a cached copy. Will that copy disappear after a certain time, because it can’t phone to home anymore?
It’ll never happen, centralised means stable. Just check out what this company called Google have built!
They are currently working hard to discontinue your favourite Google service.
And they’re being sarcastic.