Well, flying the other way around...

I was booked on an AF flight in March as a CO codeshare CDG to IAH. My check-in with AF went ok even though my ticket said CO (in the past... I've found some "codeshare operations" to not be so passenger friendly).

Two hours later, as I tried to enter the jetbridge to board, the gate reader rejected my boarding pass. The gate agt tried it twice, then turned around to her computer to check things out. Her response was "Ohhh ... You've been upgraded to L'Espace127 (Business class)". I figured they were oversold in coach, ad upgraded all the AF eilites needed, then moved to upgrading CO elites (I'm Gold) to handle oversolds. However; during the trip, I walked back thru coach and saw several open seats ... including my original aisle.

I wonder now if...
Even thought my ticket (which was an extremely discounted internet/winter fare of $280 DFW/CDG/DFW) wasn't "upgradeable"; maybe CO purchases so many "biz" and so many "coach" seats on each AF flight; and if after CO has gone thru all upgrade procedures, they uopgrade any elites like they do on a domestic trip ... under the philosophy of "we paid for the seat so we'll put anyone we want in the seats". The service was great and the food was just fantastic !!!!