My mother recently had an itinerary where both her flights were this flight - the PHL-ATL leg on a Sunday and the ATL-PHL leg on the following Saturday.
(It looks like as of Tuesday AA 1992 becomes a DFW-SEA-DFW flight, but it's the same sort of thing.)
I figure this isn't a problem as long as the two legs are flown by the same plane. But what if the PHL-ATL flight were delayed and American decided to fly the ATL-PHL flight as scheduled with a different plane (say because lots of people booked on that flight had connections at PHL?) That seems like it could create trouble.