AA may have decided that if people become too reliant on the inbound flight info, which indicates a delay(or cancelation), then they may not show up on time and miss their flight that ended up going out on time with new/subbed equipment. Veteran FT'ers know better than to do this without being triple certain, but the occasional flyers may misuse this info and the airline personnel is left to deal with rebooking/rerouting and customer ill satisfaction.