I recently had a round trip flight from YYZ to MCO. I was booked on my Latitude Flight Pass and my fiancee was booked using Aeroplan points. When I got to the gate I asked if I would use my upgrade certs (I am prestige). She said I couldnt because they cannot upgrade AP flights. I said OK and walked away. She came running after me saying they could do complimentary upgrades. Ended up flying Executive class there and same thing happened on the way home.
I dont expect it every flight but it was nice. I will be asking at the desk for every leg of my RT YYZ-YVR-HNL in Sept. Maybe we'll get lucky again!