Not that I agree with the root comment, but China is not that large without Tibet, Xinjiang, Qinghai, and Inner Mongolia. These provinces also have the least population densities - the terrain doesn't support it.
I just can't agree with what you are saying given all the land and resources they already have - sounds like the Chinese version of Nazi Germany's "Lebensraum" to me. But you have a right to an opinion and I hope it doesn't come to that.
It seems like a plausible sentiment for the CCP tho. They seem to be taking their turn as a colonialist. e.g. The "re-education camps", South China sea, tibet, Taiwan, Hong Kong, and even countries like Indonesia where they have captured the government and pro Chinese policies are being rammed through.
