YVR-JFK is a route of neccesity rather than one of economic advantage. It will be axed in a heartbeat.
However, that said, I can see a market for 2 daily flights to Western Canada. Possible one 744 and one with a smaller aircraft.
"The A340-300 may boast a long range, but the A340 is underpowered" -- Robert Milton, CEO - Air Canada