Agreed. It seems crazy to cancel a SE on a refundable J ticket ahead of a casual traveler on a basic rewards ticket. I wonder if the process isn't actually perfectly random.

This is also interesting: "Alternatively, you can also convert your ticket to an Air Canada Travel Voucher." I guess that's not all that unusual for AC, but if they randomly cancel you, you get a voucher, not a refund (if you don't wish to rebook).