The article can be misleading--it claims that many recent graduates are finding high-level positions at international companies. The fact is, the companies are hiring recent grads while repatriating the older employees so that they can cut costs. The reason that these jobs exist is because there aren't enough local Chinese qualified in these fields. But, there are plenty of Chinese studying these fields, and they will work for far less money than a recent American grad. As more educated Chinese break into the market, there will be fewer jobs for those expats.
The standard of living is mentioned in The New York Times as a driving factor for the migration, but it doesn't mention what the living situation is for these expats. Many new expats in such positions see the standard of living and become obsessed with the fact that they can afford anything and everything in China. This is an attitude that can be detrimental to expats living on much lower salaries (i.e. EFL teachers). I saw the way some expats lived in Shenzhen, and it was uncomfortable to me--it was as if they weren't living in China at all. These tend to be the people who don't learn much Chinese and don't bargain at markets, thus making things more difficult for those who don't live the same lifestyle.