In the US, they wouldn’t be allowed to use that data to underwrite policies:

https://www.healthcare.gov/how-plans-set-your-premiums/

That can easily change, though.

Define "easily". As I understand, it would require amending the Affordable Care Act. Assuming some rules are still being followed at the federal level.

That is well within "easily". One party controls Congress, the White House, and SCOTUS right now, and they're quite notably not showing much restraint right now.

And how many laws have they passed? Apparently it's not so easy, is it...

Congress hasn't really been functional in decades

> And how many laws have they passed?

Few, intentionally: a strategic decision has been made to use control of Congress as a shield for executive dictatorship, rather than using it to pass laws, with the attendant public debate and recorded votes.

They’re busy dismantling entire departments by executive fiat. When they’re done with that, we’ll see.