I really would not worry about it, though I would buy travel insurance now for whatever company I use.
I generally avoid AC because of lousy service and their proclivity to lose baggage. My TA last year suggested Air Transat over AC (at similar prices), saying that Air Transat loses a smaller % of suitcases and has newer planes. That said, AC is up to most North American airline standards (which is not saying much). You will get much better service on Mexicana (and Air France, Thai, Qantas, KLM....) though - all airlines I've used recently - for about the same price.