Residence permit valid after work visa cancellation

You will not be overstaying immediately after leaving your job but should be very careful on what will happen next. If your old company chose not to ask you to cancel your residence permit in due course (10 days after the cancellation of your work permit) then the local NIA reserves the right to cancel your residence permit by promulgating your full name, date of birth, passport #, country of citizenship and residence permit # on their website. You will have 10 days to get an exit visa if you are still in China, and if you do not present yourself in 10 days your residence permit will be cancelled and you will be legally overstaying your welcome.

Technically speaking you won't be overstaying if you can get an exit visa on time or leave China before all this happens (leaving won't stop it from happening), but this kind of public shaming may result in identity theft. The chance of this happening depends on whether the local NIA gathers this information from other governmental departments or from a tipoff from your old employer.

Thanks for the info, would you happen to know where the NIA would post this information if the residence permit and visa was linked to Shanghai? I cannot seem to find where they would make this information public.

Also not sure if anyone would know if in the current situation this would not apply for the first 60 days because of the automatic extension everybody is getting because of the Covid-19 travel and visa restrictions?

Not 100% sure about Shanghai, but for most municipalities they are on the websites of municipal Public Security Bureaus. The automatic extension is a bit tricky if your work permit is cancelled given that the NIA specified one can voluntarily apply for an extension (or an exit visa) or do nothing and get the 60-day automatic extension, but they did not say whether the two can be done at the same time.