One reason that AA needs to exit Ch 11 as soon as possible is that it probably can't order the 200 or so 70-88 seat Embraer and Bombardier RJs until the POR is confirmed. It's one thing to continue existing deliveries of earlier-ordered 737s and 77Ws, but a massive order of RJs (that the manufacturers have already said they expect) probably doesn't fly while AA is in bankruptcy.
Another reason for a speedy exit, of course, is that every month in Ch 11 costs another $25 million to $50 million or so in legal, accounting, advisor, investment bank, parasite, etc. fees.