"They will of course comply with law enforcement."
To turn over your public data?
Law enforcement can even form their own appviews, to whatever degree it would be given, why would they even need BlueSky's cooperation?
It'd be one thing if BlueSky was a natural hotbed for organizing and contained a lot of access logs and private data or somesuch, but that's not what it is or even can be.
If you are worried about censorship, may I also suggest that being hosted in the US is the least of it.