https://www.yahoo.com/news/nyu-professor-living-shanghai-says-084155922.html

They were told 4 days and now it's been 2 weeks. So the American prepper wouldn't have too much an issue of no food. But I don't think China has a prepper mentality. 

Then add in the killing of peoples pets and quarantine camps, that's another issue.

By the professors tone, it seems like he has to be careful of what he says. No 1A in China. There are vids of the bad stuff going on, and of course you won't find it on the main stream media channels. 

Then factor in how many would be able to afford to buy that much food prepper style wise.  Going based on my Taiwan XP, to have hundreds of dollars of extra food for long term storage would be difficult when your income is $600 US dollars and your rent is $60 US dollars.