Actually, this is a great idea - assuming the agents who answer the customer's call-back are empowered to change/protect the customer on alternate flights.

The DCA agents are usually very good at proactively moving people around as the later afternoon flights start getting hit with delays into EWR. I don't get called, but when I see the flight 1 or 2 before mine start to get hit, I get to the airport early and usually find out I've been moved one flight back.

Now if they could only fix EWR ...