Bunk: I would have preferred UA to step up to the plate here and also push for LAX-PEK ; I much rather prefer PEK now for connecting. Same airport for domestic and onward. Even LAX-PEK-SHA is better for me than LAX-PVG

Plus with Shanghai Airlines leaving the system (merging with China Eastern which will be Skyteam) there is NO proper feed partner in PVG (Air China is NOT a big presence)