This story is being highlighted on WeChat in China. However, it has been posted a total of 4 times, that I know of, and each time has been 'taken down' very quickly. It was there at midnight last night but had gone by the time I got up at 6am this morning. It reports that a total of 1800 foreigners have been arrested, of which the 229 you mentioned are also cited.

Anyone currently working in China without the 'proper' qualifications should be worried right now. Those who are legal have nothing to fear.
Visas and diplomas are being checked. It said nothing about degrees, only 'diplomas', but who knows. The police 'bonus' of RMB2000 per arrest is fuelling this crackdown, (if one can call it a 'crackdown'), beyond belief. It appears to be mainly happening in Beijing and Shanghai, but is likely to spread to other cities due to its popularity amongst officers of the PSB.