A co-worker of mine just returned from visiting mainland China. She said everyone she spoke to, did not know about the protests in Hong Kong. They had no idea that something was happening there.
Don't underestimate the "them and us" mentality in China. It's very pervasive. Your co-worker was assuredly on the "them" side of the equation.
Considering the humiliation that the colonisation of HK had been for 100+ years and the resulting nationalistic tendency of the people, if CCTV (Chinese state TV) had shown the pictures of armed protesters storming the HK parliament and some of them flying the Union Jack then the Chinese government would have been forced to fall on the protesters like a ton of bricks.