As closing arguments are read on the US vs. B6 // AA, here's an inconvenience likely caused by this partnership:
Friend is flying JFK-ORD today, B6 sold and operated. Flight cancelled at boarding time, rebooked 9 hours later.
The next available flight (with wide open space) marketed by B6 is operated by AA. GA refuses to rebook on that, sends him to customer service to be rebooked.
I tell him he can just book the AA, thru B6 no less, and cancel the other one free. New flyer, wants to go the rebook route.
By the time he reaches the counter, AA flight is Y1 F1, fare is $1200. B6 will not rebook, saying that the flight does not have partnership eligible space - sure enough, the B6 app no longer shows the flight as available.