Moving to a city doesn't majically get you a job and livelihood. There is already plenty of depopulated country side with plenty of livable space, people go where the actual jobs are.
True, but my point was that in China the government exerts a lot more control on where people can go. Wouldn't surprise me that the Chinese gov't could fill an empty city if they wanted to.
I don't think that is true. Sure, there is the hukou system, but migrant workers have been free to move around since the 90s, and they do.
If you handed out hukous in 3rd tier economically depressed new cities, I'm not sure if there would be many takers. And the properties in Kangbashi are all fairly high end anyways, the city hukou-deprived migrant workers probably wouldn't even be welcomed.
China builds a lot of subsidized public housing on the city outskirts of major cities, but no one wants to live there because transportation is bad to where the jobs are.