It is a joke post, but one that strikes a nerve. The definition of what is and is not the fediverse is a fierce debate and one that has not at all cleared up or gotten easier.

"I'd just like to interject for a moment. What you're referring to as "fediverse" is in fact "the ActivityPub fediverse", or as I've taken to calling it "AP fedi". The fediverse as a concept transcends specific protocols and implementations, and encompasses bluesky and atproto ("AT fedi")" via bsky.app/profile/retr0-id.tran