I think we can all agree that, at a traveler level, the status quo for skiplagging is sufficient, in that, go ahead, but accept the consequences should an airline decide to apply them.
The major question at hand is weather a company's revenue model should be allowed to be that of helping others to explicitly violate the terms and conditions of another company. I think it is fair for AA to feel harmed and to file this lawsuit.

My gut feeling is that AA will win and be awarded some amount of damages.