I have my friend booked on CX807 ORD-HKG later this week and I can testify that CX could probably be better in notifying guests about disruptions. They decided to zero-out the flight since last week, probably last Thursday, and last Friday (or so) the AA codeshare flight is shown as Flight Cancelled. However, the CX flight was still in the system until yesterday when it was finally canceled, and she was moved up to Thursday's flight.

If AA knew the flight would be canceled last Friday, why did it take CX one more weekend to figure that out?