As an American in the US, I get quite a bit of foreign and foreign language content under For You.

This is the inverse to the situation you describe but it makes me doubtful that non-US don't see a lot of American content.

The algo bends to your interests. But it's trivial to test the default reach if you ever post a video. They show stats for viewer location.

You can even find guides by people trying to make their phone seem american so they can reach us audiences.