If United is furloughing, everyone else is gone too. Time to work on your Real Estate license or open a Vape Shop - I’d take UAL over AA of you had the choice, but I’d take an AA number today while you wait on your UAL class date - because I’ve seen hiring grind to a stop and clad dates disappear.
It is just business when Pilots hop between carriers, and isn’t a black mark on your record if it isn’t a trend across your resume.