^ Yep, that's exactly what it does.

I agree with others about not cancelling the ticket and hoping for a schedule change or IROPS. If AA wants to charge $200 to reuse the ticket and won't give you anything in return for giving them a heads up that the seat isn't needed anymore, why bother?

Most domestic tickets are usually endorsed with something along the lines of "CXL BY FLT TIME OR NOVALUE", so the last possible moment to cancel is just before the plane pushes. If there are no schedule changes or IROPS, let the gate agent know that the passenger is no longer flying to have the itinerary cancelled and possibly retain a residual value of the ticket if the change fee isn't more than what you paid for it.