Pretty sure China's not an ethnostate, as much as the CPC would want it to be, and pretty sure the lack of internal division is from their atrocious suppression of minority groups.
Less than 5% of the Chinese population is non-Han. I think the Manchu are the single largest minority and their language is for all practical purposes dead, along with any living distinct culture.
Doesn't make what he said false though. If your state caters to mostly the wishes of the 93% majority suppressing others, you can effectively consider it to be an ethnostate for arguments.
