I'll front end load with the fact that you probably can't go wrong. This career, especially when treated as part time, eclipses almost every job out there.
That said, consider the following.
I have little confidence AA will expand PHX. It is a company helmed by low rent bean counters; they'll trip over a pile of gold doubloons to pick up wooden nickels. An example: How long has the hiring/retirement wave been discussed? Should it have caught anyone by surprise? Well, it caught AA management off their guard, and they shut down their Phoenix training facility despite having the data. That place would be worth its weight in platinum right now.
If you pick PHX and want to do any other flying at AA you will have to commute. Captain upgrade, widebody, anything other than A320, those will all force you to another base.
I would not put money on AA getting a new contract in under 24 months.
I know very little on the topic, but AA is supposed to be getting new scheduling/trip trading software that's allegedly worse than what they have now. Hopefully someone else can speak intelligently to it.
If you want fly out of PHX be warned: America West produced some of the worst pilots I've had the displeasure of flying with. By the same token, I've sat in the jumpseat with SWA many times, and they almost always seem reasonably competent.
Retirements matter most if the seniority list doesn't shrink. AA won't be able to do any growth hiring for some time due to the fact the seniority list shrank a great deal during covid. Management is trying to get everyone excited about all the pilots that are getting recruited; however, all those people for the next 18 months will barely cover what the company is making up for since spring 2020.
That's the worst of it for AA. The plus side is meteoric seniority movement, good overnights, easy flying, and a great job overall if you don't let yourself get caught up in the bullshit.
SWA is hiring for growth; that can get you stuck at the bottom of the seniority list for a long time.
SWA is not the same company Herb founded. Hopefully they can hang onto what's left of their culture.
SWA typically has much better scheduling flexibility.
Why mention all of this? Because despite how tremendous it is to get paid to fly jets, no matter where you end up, the above statements (along with more creative complaints) will be brought up CONSTANTLY on the flight deck. Then you'll start to second guess your choice of carrier; do yourself a favor: Don't. Bloom where you're planted; enjoy your days off and live your best life.