I was expecting to meet an old friend today in SFO. He was taking AC #26 PVG-YVR and then connecting to a UA flight to SFO. When I checked with AC, I found out 26 has been canceled today but no reason was given and I haven't heard from my amigo. Does anyone know why 26 was canceled and what the protocol would be to reroute pax to their destination cities? I think AC service to/from China is pretty limited. Thanks.