> ... "under this definition, bluesky and friends, dsspite all their talk, really does fit in the centralized camp."

In my mind, I put them somewhere in-between, leaning a tad more toward "centralized" because they still rely on an individual to host the service no matter how "federated" they are. Until they're truly peer-to-peer, there's still that aspect of centralization involved. We need something kinda like BitTorrent but for messaging / social connections.

Maybe Bluesky is analogous to Github, if the AT protocol truly does allow for migration away to an alternative?

Although Git repositories are portable, PRs, issues, actions and such aren't — so even if the migration away from Bluesky is lossy the comparison seems apt.