Guess we know some other reasons why BA and One World are out and SkyTeam:
Delta, Air France, KLM are in:
https://www.otc-cta.gc.ca/eng/ruling/274-a-2016
WestJet, on behalf of itself, Compass, SkyWest and
Delta, has applied to the Canadian Transportation Agency (Agency) for an approval to permit WestJet to provide its scheduled international service between Canada and Mexico
by selling transportation in its own name on flights operated by Compass, SkyWest and Delta between the United States of America and Mexico, for a period of three years or such longer period as may be authorized by the Agency.
https://www.otc-cta.gc.ca/eng/ruling/266-a-2016
WestJet, on behalf of itself and
Air France, has applied to the Canadian Transportation Agency (Agency) for an approval to permit Air France to provide its scheduled international service between France and Canada via the United States of America, and between France and beyond Canada to the United States of America,
by selling transportation in its own name on flights operated by WestJet between Canada and the United States of America, for a period of five years or such longer period as may be authorized by the Agency.
https://www.otc-cta.gc.ca/eng/ruling/267-a-2016
WestJet, on behalf of itself and
KLM, has applied to the Canadian Transportation Agency (Agency) for an approval
to permit KLM to provide its scheduled international service between the Netherlands and Canada via the United States of America, and between the Netherlands and beyond Canada to the United States of America, by selling transportation in its own name on flights operated by WestJet between Canada and the United States of America, for a period of five years or such longer period as may be authorized by the Agency.