Part of their marketing seems to be to create confusion about it. Bluesky uses the language and values of the fediverse to promote what is essentially another closed network. Meta is also doing this with Threads. Bluesky seems like a chill place and a lot of decent people seem to be very happy there, and they provide a lot more user controls than other networks, so the comic definitely still works.
It sort of depends on how you define fediverse. If you mean things using the ActivityPub protocol and are federated with Mastodon, Lemmy, etc. then no, it's not part of the fediverse. If you mean anything using federated technology then you could possibly include it. https://docs.bsky.app/docs/advanced-guides/federation-architecture It uses something called AT instead of ActivityPub. I'm not personally aware of any other services or instances using it, but I also didn't look very hard.
Edit: I learned that the term AT Protocol uses for their version of fediverse is "atmosphere". So I wouldn't necessarily say it's part of the fediverse, but the context of the usage matters.
Edit: After digging in a bit, I believe the thing most people would consider as "running an instance" would be an appview and/or relay. Both of which they claim are ready, I just haven't seen any. I think that part of the disconnect is that in ActivityPub the roles of what AT Protocol calls PDS, Relay, and AppView are all handled by a single instance. A PDS stores canonical data, a Relay aggregates PDSes, and an AppView is a UI reading from a relay.
It sort of sounds like they're trying to "have their cake and eat it too." It will be interesting to see where things go with it. I hope they choose to be more open with federating instead of trying to become Centralized Twitter 2.0.
Agreed -- I will say, being able to host your own data is already a huge step away from traditional social media, so I'm not shitting on Bluesky by any means
BlueSky does not support federation in any way that we understand the word.
It is 100% reliant on the corporate server(s). They do offer a way to host your own data, which solves a singular problem with corporate media, which seems to be what they mean when they promote it "supporting federation." Is also has an open codebase, which is something.
As an aside, I have read in some places that self-hosting is very straightforward, and in other places that it is prohibitively difficult. I have basically no idea about any of these things.