Turkey's interest in Uighurs is far smaller than Turkey's interest in its own economy, and China is spending a lot of money to prop Turkey up - they're buying influence. Needless to say that making an enemy of a security council veto power while you're allied with the remnants of ISIS, annexing parts of neighboring countries etc isn't a wise choice.

Erdogan may seem unhinged at times, but he's not, his steps are quite rational from an empire-policy perspective.