Blacksky has already built their own ATProto stack that's fully independent from Bluesky.
Now Eurosky is making progress as they roll out their own PDS.
I see more independent infrastructure springing up on https://atp.fyi/network, including AppViews.
For anyone hoping that we'll get another wave of people coming to the fediverse once Bluesky folds/enshittifies, that might not necessarily be the case as people will have more options to stay in the Atmosphere.
Case in point: Northsky just sent out an email update about beginning their "phase two": 26% of their users have already been migrated to their new PDS, now they're moving on to creating their own app, moderation labeler, support for private data, "and more".
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