Amplifying shows of division in a country promotes the view that said country is flawed and weak, in this case along racial lines. China has plenty to gain by showing that.

Exactly! So demoting those videos suggests that China is not using the algorithm to promote anti-american views.

That seems entirely speculative. There are plenty of other reasons to hire them. Can you provide evidence for your claim?

No, CIA agents don’t go around saying they’re working for media companies to disseminate propaganda, and media companies don’t broadcast that they take extra care to make sure their coverage lines up with the state department’s narratives.