I’m about to do AA4367 YKF-ORD and when you click Track Inbound Flight, it takes me to 4086 ROC-ORD. The plane is coming in to YKF from ORD as 4282, so the information is incorrect on FA.
Usually the case is that the carrier has done a tail swap but hasn’t updated the aircraft for the further downline flights yet. It usually sorts itself out prior to departure. It could be the case that there currently is no aircraft scheduled for that flight and that the aircraft scheduler will see what he has available shortly before the flight.