That’s a known fact, China spies on their own citizens and has concentration camps for the Uighurs. And since it’s China’s app, of course all of the data goes through China. That’s like saying all the data on Twitter goes through America (which the government can legally use against you). They have more ways of spreading propaganda than just in Tik tok. And YouTube has the same algorithm that recommends you videos based on what you have watch (or they try to at least, they can continue actively failing).