Depends on your perspective. Would it be fine for Meta Threads to replace it? Threads supports ActivityPub, so in some ways it likely interacts better with the fediverse.
If we agree that Threads isn’t a suitable replacement, then clearly there’s some criteria a replacement should meet. A lot of the things that make Threads unpalatable are also true of Bluesky, particularly if your concern relates to the platform being under the control of a corporation.
On the other hand, from the perspective of “Twitter 2.0 is now a toxic, alt-right cesspool where productive conversations can’t be had,” then both Threads and Bluesky are huge improvements.
Unless something has changed, it did. The page linked reads:
The link takes you to their repos. The server repo has instructions on self-hosting directly on your server or with Docker. The app repo has code for both the iOS and Android apps. That’s good, because the iOS app at least doesn’t have a built-in way to select a different backend server.
Whisper is by OpenAI and as far as I know they have not shared the training code, much less the data sets, so the best you can do is fine-tune the models they’ve provided.
If use of Whisper is a problem, but the project is otherwise interesting to you, you could ask them to consider using a different STT solution (or allowing the user to choose between different options). I’m not aware of any fully open STT applications that are considered to be as capable as Whisper, but if you do, that would be great info to share with them.