With bumps, I've had AA reschedule and/or reroute me, and sometimes both reschedule and reroute me as I've requested. For example, I took a bump for a flight heading to LGA and instead had AA agree to route me to DCA on the same day. (Saved me a DL Shuttle ticket.) Another time I took a bump for a flight heading to DCA and AA agreed to reschedule and reroute me to LGA for the next day. Of course this could be a situation of YMMV.