Call AA to avoid having the reservation cancelled. Even if travel isn't soon, airline systems purge (with varying degrees of efficiency, some having a 72 hour rule in principle and especially for award tickets including partner flights) reservations that aren't attached to matching tickets. The ticket is probably in some reissue queue and needs to be pushed to the head of the line. Sometimes it's useful to stay on the phone while the ticket is immediately reissued manually by the agent or while the agent is on the phone to their internal ticketing/help desk.

You're wise to notice this and to watch for the email with a new ticket number.