Thank you for the citation. The issue here is that 'out of work' is not a very useful phrase. Taken at face value, it just means not working and is not necessarily synonymous with unemployment in the way economists use it (i.e. actively looking for work but unable to find it).

This is possibly why queermunist expressed confusion about whether it included students. At first blanch, a ~20% unemployment rate does sound high.

I did turn up a useful SCMP article which highlights:

Since 2018, China has used a monthly survey-based unemployment rate as its main indicator. The data captures all regular urban residents, does not include an upper age limit and the [National Bureau of Statistics] claims it also includes migrant workers...

... to be considered unemployed, a worker needs to have been actively looking for a job in the past three months and be able to start work within two weeks; otherwise, [they are] not counted as employed or unemployed.

I'd like to refer back to the CNBC article (also using a 21.3% unemployment rate for 16 - 24 bracket) which notes that the unemployment for the graduate cohort appears to be temporary rather than structural. It's not an enviable position to be in, definitely, but I wouldn't say it's at the point where students will demonstrate en masse like you suggested.