The route is served by a B787 that normally runs EWR-YVR-BNE/BNE-YVR-EWR. So there would have to be a major change to AC's service to BNE or EWR for this to change to another aircraft as the logic is perfect from a scheduling point of view.

Of course, equipment changes are always possible, so say that happens, the risk is now you fly EWR-YYZ-YVR where EWR-YYZ is just a quick hop and then book any widebody YYZ-YVR to get a premium economy seat for the transcontinental.