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.