Yep, and with the new FAA pilot rest requirements, delaying the flight could have likely cascaded into the flight flown by the pilots out of AUS the following day resulting in more misconnects. Welcome to the world of unintended consequences from regulations.
Of course, we all want our pilots to be properly rested! :-:
That said, there are a number of different variable that go into the equation. AA has a team of employees on duty who are trying to minimize disruptions. I think everyone would be impressed with the amount of resources dedicated to minimize disruptions and NOT making passengers stay overnight.