I hope the line '...stays for at least 90 days' is not what the Chinese consider 'longer serving staff' because If that is the case then it shows why companies use China for their manufacturing. Treat the workers like crap and if they leave they know there is an abundance of people who will fill that spot. Not so easy to do in the West, hence why they have to treat workers better because if the worker leaves the company struggles to find decent replacements. Not so in China.
Well, at least when someone shows off their new shinny iphone 12, that person can be rest assured that it was made by a respondant and resourceful workforce that was made to force to work 24hrs a day without any holidays and mandatory overtime. Wont you be so happy that Apple treats it's manufacturing workers so well.