I have a paid American and a reward BA Avios flight on the same route that is cancelled by the airline.

My American Airlines US direct domestic reward flight HPN-MIA got cancelled by the airline. It was an Avios reward flight. I called BA and sent an email to rebook me to a direct AA EWR-MIA flight. It’s the same destination, but from another departure airport within 300 miles.

American was able to rebook me free of charge. BA is stating that it isn’t able to do so, because there is no reward availability. Is this the true policy? Because the General Conditions of Carriage only say that there needs to be reward availability when its’s a reward cancellation done by the passenger, not by the airline.

Where can I find the terms and conditions for rebookings on AA reward flights when the airline cancelled your flight?