If you search Zhengzhou many of the results from mainstream media were about ghost cities
The rest are about Foxconn's factory.
This BYD factory were build further down south of downtown.
The ghost cities are more likely to be cities previously built for mining and other activities that were gradually abandoned by young generations throughout the years. Zhengzhou should be (relatively) fine as a provincial capital as well as a railway center but I'm sure there might be a few high rising abandoned buildings here and there.