Even if people don't believe the Chinese, there are loads of foreigners who live and work in China and know Xiangang well. What they say time and time again is that the accusations are nonsense. There are mosques everywhere. The Uighur population is growing. If things are so bad, where are all the refugee camps along the border?
There are so many videos. Here's one which includes Jerry (don't know his last name) from the UK, starts 27mims02secs: