I don't expect AA's market share in PHX to fluctuate much in the nearish-medium future; there may be an upgauging of equipment with a reduction in frequencies but from what I'm seeing and hearing it looks like PHX is being better primed to do what it does already, which is accommodate a large number of tight, narrowbody connections. A lot of money is being spent to this end and other improvements in tech, equipment, and facilities. Most of the gates on the N1 and N2 concourse are going to be re-aligned to allow nearly all of them to take A321's (and possibly 757's) so that we can service even more of those at a given time. What I've been hearing and what I believe Kirby said at the last town hall was that PHX will be seeing a lot of A321 and B737-8 activity with A320's and A319's being reduced over time.
The key to PHX is scalability with demand for domestic air travel. We already see this with the calendars consisting of FLEX, regular ops, and reduced-ops days. When demand is high PHX runs on all cylinders, almost bursting at the seams; when demand is low operations are limited to reduce costs. This makes staffing a huge pain the the butt but it's a profitable practice as it allows PHX to grab the demand when it's there and retract when it's not.
According to the route map, DFW serves nine markets in California, LAX serves seven, but PHX serves fifteen. I just don't see LAX and DFW being able to as efficiently provide the coverage, frequency, and volume that PHX does to California. Let LAX focus on perfecting O&D offerings there and let PHX do the heavy connecting in the West.