But Imperial China always extended their borders as far as administration made possible. They didn't care about which ethnic groups were in the empire as long as they paid up, so they were not for the desire of a homogeneous society, that's a modern revision.
He is right however that China doesn't have a racial caste system. For China, it's all "to each according to his abilities and needs". Your ethnicity doesn't matter, if you are a positive influence, you're welcome on equal position to any of the native born Chinese.
But once China has cleaned house with the other hegemony contenders, there will still be an imperial order of sorts, that's what China's historical heritage and pragmatic interests requires.
The restored Imperium would have current China as its core 1st tier provinces, in charge of supplying advanced goods, scientific development and military protection. Asian countries + Russia would undergo (mostly) peaceful sinicization and become 2nd tier provinces, providers of their own brands of innovation, industry and goods, in friendly and fair competion with the core. Finally, everyone else will be deindustrialized and provide resources, tourism and manpower, which will still provide them a fair living standard, but make the peripheries unable to challenge China directly, avoiding another USA from rising up in the future.
This exchange of privileges is how it has always been in the known world whenever China restored itself. Then after some period of time, the core would internally deteriorate and divide because of unreliable successors. However, thanks to modern technology, that will likely never happen again.
