I am still confused as to how you can cancel on line, based on my example.
I have a current Avios.com Reward Booking which now shows in my BA account under MMB .
if I go to try to cancel, this is what I get;

This is a trade or travel agent booking
Trade bookings, or bookings made through a travel agent cannot be processed by British Airways.

Is it not the same with Alaska ?

I also have an Avios Reward booked through BA themselves and again I cannot see a way to cancel ?