The document describes proof of effectiveness as supported by demonstrating "non inferiority to... a US licensed product". So yes, a (licensed) benchmark, but I see no references to a requirement for only testing against the best standard of care. It's a separate question about whether it should be though, and the cfr is quite vague throughout, so I would probably expect this isn't an illegal move (assuming arbitrary and capricious isn't held by a court), but I don't see it supported by precedent.