Which means it could just be a documentation bug since there are quite a few and some old bugs in the docs reintroduced when the new docs were added. The phrasing about “matching” has only recently been added to the docs (and in some cases removed by accident in this update). So the docs are incorrect in a bunch of places especially round the subject of oAuth/what token is needed.
It is safe to assume that for endpoints using a scope, the broadcaster_id must match the user_id that the token belongs to.
Are two examples