It is estimated that it will be assimilated. I remember listening to Yuan Tengfei talking about the Northern Dynasties.

Liao occupied youyun 16, and the result was assimilated by Han. Now we can't find Liao's descendants, we can only confirm them by DNA.

Manchu people in Qing dynasty, few Manchu people can speak Manchu now, and most Manchu people have been assimilated.

As for the Mongols, the final result of not being assimilated is being driven out of the Central Plains.

So basically the aliens who invaded the Central Plains.

Either assimilate, get married, and finally get rid of each other.

Either be driven out of the central plains, not assimilated, and continue to live a life of flying on the blue sky and white clouds.