Indeed, AC (and whoever else owns the plane) has probably made a substantial profit on this hull and will have already received the cheque! ...
BA got paid immediately and in full, for example, when a perfectly serviceable 747 was stranded in Kuwait after the Iraqi invasion. It was the oldest hull in the fleet and earned the company a nice profit. .
I believe this is incorrect. Unfortunately people compare aviation insurance to their more familiar car (auto) insurance policy, and make wrong conclusions.
Cars rapidly depreciate. The old joke is, as soon as you drive a new car off the lot, you've lost 50% of the car's value. So car insurance works with this concept in mind. In case of a total loss, the payout is based on
Actual Cash Value, which takes into account the age of the car, wear and tear, mileage, etc. All these things are
subtracted from the car's replacement value (depreciation).
In aviation, things work very differently. The replacement value of an airplane doesn't follow your typical depreciation scale. Even a Cessna 172 sold for $20k back in 1975 might be worth $45k today.
So in aviation, instead of using Actual Cash Value, the payout is based on a fixed
Agreed Value. I pay $X dollars premium, and the insurance company agrees to pay me $Y dollars if there's a loss.
There is no depreciation involved.
People conclude: wow, if I crash a 30 year old plane, the insurance company will still pay me $Y dollars, which must be way above the depreciated value of the airplane!
But we've already shown that that's wrong, with the Cessna example. At the time of the claim, the replacement cost of the airplane might actually be greater than the Agreed Value.
Companies like Air Canada (or British Airways) do not like to under-insure or over-insure. If they under-insure, then they have to shoulder tons of expenses if there's an accident. If they over-insure, then they are overpaying their premiums.
So periodically, airlines will get experts to re-appraise every aircraft in their fleet, and re-adjust their insurance requirements accordingly. So if the value of an aircraft drops over time, they will re-insure the aircraft at a lower Agreed Value, and pay less premiums.
Thus in reality the delta between the Agreed Value and the replacement value of the aircraft isn't very large, unless either the airline or the insurance company hasn't been doing their job.