I saw a documentary once about two ghost cities, the documentary was 6 years old and those cites were almost with 0 resident, I saw on comment Chinese people saying that those cities are full now. It's just China being two steps forward.
Maybe this is the precursor to the next step of "seeding"?
Right now, under the hukou system (https://en.wikipedia.org/wiki/Hukou_system), you can't just move anywhere you want. What ends up happening is those living in rural areas illegally move to cities like Beijing/Shanghai/Shenzhen for work, but can't get their children educated or get healthcare. This is a way to prevent mass migration to the first-tier cities.
This is why stuff like this is important. We get a view behind the propaganda veil. The narrative of "See, we planned ahead all is good," is questionable especially considering their recent stock market and economic woes.
It's more like TV channels and newspaper trying to give you news that blew your mind, 2010s marketing = WTF effect.