Earlier in the thread I've read that the 889 YVR-JFK-YVR sector will be cancelled. If this is the case, how will the schedule work for the 889 service if it wants to depart YVR around 12am? Does that mean they will need to depart HKG 6am?

I've been a veteran of NYC-HKG-NYC and I've flown in all 3 flights. I've noticed the 10 a.m. flights are usually full, but the 3 p.m. flight is almost never full. So I guess they are banking that if they reduce the NYC-YVR flight, then those passengers will move up to the 3 p.m. flights. Makes sense economically, 2 full flights is better than 3 partial flights. Besides, if YVR-HKG-YVR are in high demand, there's no reason to have YVR-NYC-YVR since this particular route is not in high demand.

Someone can correct me if I'm wrong, but the current 888 flight leaves HKG late at night and arrives YVR the same evening, I think around 8-9pm. So the plane can sit there for a few hours and then turn around and head back to HKG as 889 sometime around/after midnight, with an early morning arrival.

Loads are only one part of the equation - yields and costs matter too. NYC-HKG is likely the most expensive flight to operate in the CX network on account of the increased costs of ultra-long-haul flying.