Chinese government has been running a program of cultural unity for some time, with low key assault on Uyghur culture and Han colonization of their lands, similar to what they are doing in Tibet. Then Saudia Arabia upped the stakes by financing the radicalization of small fraction of Uyghurs, leading to some terrorist attacks, bringing the attention of Chinese government to Uyghurs. Then Saudi Arabia threw them under the bus to keep good relations with China (they deliberately used radicalised Uyghur expats as shock troops in Syria) and Chinese government rolled out program to stamp out Uyghurs, not unlike to what various emperors did to conquered people as China expanded through centuries. Compared to them, Romans were utter amateurs.