Counties like US who themselves did and support killing of thousands of people including Muslims don't sound good talking about Muslims in China. It's more like a pissed of political reaction then worrying about a community.
China is not rule of law kind of place. They will agree to all kinds of things and then turn around a flout them with insouciance as they see fit. Heads I win tails you lose.
The previous US Secretary of State declared it an act of genocide.[1] Has the current administration carried that designation forward?