Originally Posted by
CloudsBelow
Think that's a slippery slope and doubt it will happen. IF AC specifically charges $x for 767 over HD and the 767 goes MX to be subbed by HD, Does that mean AC owes all passengers that '767 premium' back?
That's why I provided an example of where it's already happening

. And I have been on the example route when subbed before, no credits are not given as they are still getting you from A-B on time.