I have an upcoming SkyMiles business class itinerary of which all but one flight is operated by AF or KL. Knowing better than to trust delta.com, I've secured all my seat assignments on the KL and AF flights through klm.com and airfrance.com, only using delta.com for the final DL-operated flight.
Here's how the respective airlines list my seat assignments.
Flight 1: IAH-AMS on KL
AF: 77K
KL: 77K
DL: 2K
Flight 2: AMS-CDG on AF
AF: 2D
KL: 2D
DL: 2A
Flight 3: CDG-destination on AF
AF: 2B
KL: 2B
DL: 1G
Flight 4: Destination-CDG on AF
AF: 2F
KL: 2F
DL: 2A
Flight 5: CDG-AMS on AF
AF: 2D
KL: 2D
DL: Open seating
Flight 6: AMS-JFK on KL
AF: 2A
KL: 2A
DL: Select seating [hyperlink]
Flight 7: JFK-IAH on DL
AF: at the airport
KL: Select seat [hyperlink]
DL: 2C
I find it amusing, albeit perturbing that delta.com is wrong about my seat assignments on every one of my partner flights. Not content to be simply unaware of what seat assignments I have, delta.com flat out invents seat assignments on its own accord. And only delta.com thinks it makes some sense that CDG-AMS on AF is "open seating," but AMS-CDG on AF accepts assigned seats.
If delta.com can't mirror accurate and true seat assignments secured through its operating-carrier partners, then wouldn't it make much more sense for it to direct its passengers to its partners' websites or telephone agents instead of inventing fictitious and misleading seat assignments?