Who decides what's "metadata". Even with TLS you can still workout what site someone's visiting because the hostname is exposed by SNI (and if it's not SNI, then it's a single IP per hostname so you can just check it).

The hostname tells you when someone's visiting a rape counselling forum or a STI website or a whistleblowing site. It tells you what their political perspective is, their media landscape.

That's data the FBI can already get.