Orthan is right about whether this would be a commercial success. That's a whole other problem to the engineering one of achieving the performance.
In any case, this is about a project that is planned. Granted this is well above just ppt or model level, there is a lot of work left to make this, mass transport possible and commercially viable.
Sections of the Beijing-Shanghai and Beijing-Guangzhou lines are already at full capacity.
So if you're going to build yet another new line, it might as well be a faster one if the economics can work out.
Distance wise, Beijing-Shanghai is 1300km which means a Maglev would should take less than 2h20min.
That is short enough for premium ticket charge for travellers on day-trips for leisure or for business.
Currently there are 210 million passengers per year on the Beijing-Shanghai line.
And if I look 10 years ahead, there's probably enough demand on this route for another 200 million passengers per year.
There are major traffic nodes at either end of the line: Beijing-Tianjin and also Nanjing-Shanghai-Hangzhou
A similar calculation applies to the Beijing-Guangzhou/Shenzhen route which is much longer at 2200km.
That also means there are more city-pairs which have viable journey times of 1h30min - 5 hours