The AOA can and will do nothing.
They lost the fight with CX management the day after the 49-ers were fired. If the fleet had been grounded that day they would be in a totally different situation today. As it turned out, all flights departed, operations were normal, because the fear-factor entered the equation.
Battle lost, management won. And they will win the war.
To resist the AHK situation is futile. Management will get their way, CX trainers will do as they're told and train AHK new-joiners on the -400.
Why? Because fear is factor for all of us.