I don’t know why anyone would be surprised about this. Bluesky is a distributed system using an open protocol. The whole point of it is that there’s no central control.
Same goes for the Fediverse, of course. Everybody should be prepared for the “surprise” that all our posts and comments here are also being used for AI training purposes.
From the Bluesky TOS:
…
So looks like the Bluesky TOS simply doesn’t apply. Create a developer application and give it whatever training-friendly TOS you want.