Some say they will go back on retirement. But at that point it doesn't really matter.
So after a decade or two,you are neither here nor there, essentially "shipwrecked" in America.
In high school, I had a lot of ABCD classmates, and there parents were incredibly successful in the Seattle area, especially at Boeing. They had no problem going into management.
The fact that I can guess the company implies a glass ceiling.
And that's with a white girlfriend!
Besides, did anybody realize how much chinese are contributing to high tech, battery tech from a chinese guy at stanford. Math from many chinese.
That said, of course the chinese government will want to take advantage of this like the russians will with their emmigres. The scale though may be frightening.
When your country is poor, moving to the U.S. offers great opportunities for you and your children. But as your country gets richer, the difference shrinks. At some point, you might find that your home country offers the same or better opportunities for you. As soon as the kids go to college (or get married), the parents are free to go back.
Too many elderly people coming back, though, could cause strain on a country's pension and welfare system. After all, they've never contributed anything toward a pension plan in their home country. Some people intentionally keep their old citizenship (even after decades of living in the U.S. and multiple opportunities to apply for U.S. citizenship) just so they can claim pension and welfare when they go back. Their lack of U.S. citizenship also makes them less emotionally attached to their new home and less involved in the public life of the U.S., making them even more likely to go back.
On paper, there is no comparison between American and China. Cleaner air, food, and water, better Transportation, more stable government, etc. But eventually these immigrants hit a ceiling at work or miss some intangible quality about their homeland.