It's pretty clear what happened here.
Air Canada refused to negotiate in good faith knowing that the union would be forced back to work if they went on strike.
The union, lacking any other options, because the company was refusing to make any concessions, went on strike.
The government, like the good little patsies they are, immediately stepped in with back to work legislation.
And then the union, like the absolute gigachads they are, said fuck it and went on strike anyway.
Low and behold, suddenly a whole bunch of concessions materialized out of thin air.
This whole thing could have been resolved without there ever having been a strike in the first place, if not for the fact that Air Canada had absolutely faith that the government would interfere on their behalf.
Talk to your representative, tell them that the job of the government should be to support labour rights, not corporate profits, and remind them that we'll see less industrial action if workers are actually well taken care of.