I feel like this article explains it in a way that reveals a bit more of the harsh reality, but still supports your claim of Muslim nations' support of China's policies. It's also from Medium.

https://medium.com/the-diplomatic-pouch/analysis-why-muslim-countries-in-the-middle-east-support-chinese-atrocities-in-xinjiang-f4ec7d4bea48

They write plainly about the support being due to economic ties, fractured Muslim subdivisions, and "agreeing as a way to survive."

At this point our source is the same and still contradicts itself.

Again, I'll concede since I don't have a more credible answer.