AA and DL have waivers for PVG and PEK
United is still waiting to issue a waiver for PEK and PVG. Here is a part of the article appearing at USA Today.
American has two waivers, one covering Wuhan and one covering Shanghai and Beijing, China, two major destinations. For Wuhan trips scheduled through March 31, travelers can request a refund even if they are holding nonrefundable tickets. For Beijing and Shanghai, travelers with tickets through Jan. 31 can change or postpone their trip without the usual penalties.
United's waiver covers travelers with tickets through March 29 and allows refunds.
Delta on Friday issued a waiver that covers two major destinations in China, Shanghai and Beijing. Travelers booked on flights to or from those cities through Jan. 31 can change their flights to as late as February without the usual penalties. Travelers who want to cancel their trip are eligible for a voucher in the amount of their ticket, though a change fee will apply when using it.