I think we can all agree that the service patterns on YYZ-MAN mean that Rouge could easily slot in MAN-YVR rotations from an operational perspective. The real question is whether they're actually motivated to do that based upon market analysis. If they've identified an alternative route which represents a more lucrative return on the use of that B763 over those three vacant days, the aircraft will fly that route instead. Obviously I (like most here) hope that MAN-YVR will be the result of these YYZ-MAN cutbacks. But we must be aware that this is a risky assumption. Air Canada Rouge executives are loyal to their profit and loss account, not to serving MAN specifically as a priority over other airports in contention for their fleet deployment.
If MAN-YVR is in their thinking, they need to be placing it on sale soon or Air Transat will be well ahead of them.