On some flights they will need to keep a J - YYZ-YVR, when it continues on to HKG or HNK. YYZ - YHZ, when it continues to LHR... etc., you get the idea.
The idea of J on YOW-YYZ or YYC-YEG may indeed become a thing of the past.
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Your resident on-line IATA Travel Agent - When booking travel through a TA, I might suggest you NOT use anyone affiliated to ICTravel out of PHX.
Just a suggestion.