​​​​​​​AA will rebook, but the ONE redeeming quality at CLT is that assuming that the CBP is actually present at the time of your flight's arrival, they are pretty quick at clearing passengers, assuming MPC or GE, and do it in a reasonable time for regular US passport entry when compared to some of the other first entry options with AA. If for some reason you do miss your flight, you should get rebooked on next available flight to destination, but may want to check the app as sometimes the option they give is not always the best option.