It isn't at all the same. Which country is going to recognize or absorb Xinjiang, Tibet, or Taiwan? India? Turkmenistan? Turkey? Let's get real for a moment here. This whole shit show in Ukraine wouldn't have happened if the U.S. knows that there's a limitations to what it wants or wishes to do with respect to it's geopolitical aims in the world especially against proud historical hegemon like Russia and China.China doesn't support "recogniziation of independence separatist states" because what if separatists in Xinjiang/Taiwan/Tibet declare independence, I bet you will say you oppose that. But with separatists in Ukraine, it's fine because "US BAD" , that isn't any different from US supporting Xinjiang independence because "CHINA BAD". What's up with the double standards.
Xinjiang becoming a wayward province or being absorbed by any of China’s neighboring countries invites regional war and annihilation full stop. The same goes to India with respect to Tibet and Taiwan is already a red line where China will drop the massive hammer.