I think it's likely you're right, although I haven't looked for any hard numbers.

But anecdotally, I only speak English and I listen to lots of Finnish, Swedish, German, and Norwegian music.

I don't know if Spotify just started recommending this stuff based on the few metal bands I knew from those places, but it started recommending other genres too and I really like lots of it. Not sure how I'd find this music otherwise, actually.