I like the fosstodon.org approach to potential #Facebook fediverse federation:
https://hub.fosstodon.org/facebook-fosstodon-fedi
https://hub.fosstodon.org/facebook-fosstodon-fedi
Facebook, Fosstodon & The Fediverse
This is Fosstodon's official stance on the whole Facebook joining the Fediverse debacle.hub.fosstodon.org