Thanks for the quick reply AndyAA! I remember checking a couple weeks ago for our dates (leaving midweek in mid/late December, when this route was still available), but when I logged back in to book the flight AA 1913 had disappeared.
I will probably wait a few more weeks to see if it reappears but the backup plan is to fly out of DCA (my wife absolutely refuses connecting flights whenever possible and we have no status on UA, so EWR is not an option at this point lol)