I checked the schedule for next summer and it seems that while YVR-LAS remains available for sale, LAS-YVR does not. It seems likely that they are still working out the details, but I wouldn't bet on YVR remaining. It's unfortuante because over the past few years YVR has been somewhat of an outlier on the network with flights to SAN, LAX, PHL and now LAS all being dropped. Only PHX remains.