It was never AA's old trip. The route was awarded to TWA and the DOT made it clear it would not transfer to AA as part of the TWA acquisition. The criteria for the DCA beyond perimeter routes is one AA does not qualify for.
The whole idea was to give smaller carriers a shot at these routes. Hence National, Frontier, AWA, TWA won the awards, not the big guys. The original TWA award was subesquently given to Alaska for SEA-DCA some time ago.