The probable cause for this action is the conflict in Xinjiang province between China's dominant people, the Han, and Xinjiang's Uighurs. The Uighurs are more Turkic than east Asian, and in addition are Muslim. The Han make up roughly 90% of China's population and are in conflict with China's minority populations, including the Tibetans and Uighurs.
The existence of this mummy strengthens the claim of the Turkic Uighurs on their part of Western China, a claim the Han do not accept. Don't be surprised if this mummy gets "lost" in transit.