Zhengzhou New District is just one of China's many "ghost towns." China's economy depends on growth rather than profit. So, to fuel growth stats, the Chinese government has been building unnecessary housing units in remote areas of the country. Officially, in 2010, a mind-boggling 65 million homes were vacant.
The simple explanation is that China is riding a tiger and doesn't know how to get off.
But if I was a totally evil bastard ruler in charge of an evil all-powerful dictatorship that would snap to carry out my every whim and evil plan, I know what I'd do with this housing stock.
I'd conquer countries that I thought should be part of greater China and deport the conquered people to China, move around people within China, and then colonize the conquered lands with reliable Han settlers.
Taiwan, North Korea, Mongolia, and northern Vietnam could all be targets. I'd move Han Chinese into the vacant new housing stock in China while moving really poor rural Chinese Han into existing housing stock. both would consider it a reward.
I'd dilute Moslem and Tibetan presence in the western part of the country by putting them in the existing housing stock in eastern and central China (with some going to the new-built, vacant housing as rewards), including the stock vacated by poor rural Hans who move to the cities.
I'd take a large percentage of the population of the target countries and move them into the far west and Tibet where they'd be seen as Chinese pawns and resented by the remnant indigenous population. By that hostility, the new forced colonists would become effectively Han-ified.
Finally, loyal Hans would move into the vacated housing stock in the target countries to colonize the countries and secure them for Greater China.
Not that I think anything but the simple explanation is the reason for all that empty housing stock. China simply does not have the level of control to pull off such a stunt. Nor does it have the resources despite their advances and their trade surpluses. But if this was a game, I'd so totally try to pull that off.