I tried searching for a thread on AAdvantage awards on BA (using a similar format to "AAdvantage Award on JL / JAL / Japan Airlines (master thread)") but didn't return any Google results.

I used AA miles to book two business class award tickets, BKK-CMB-AUH-LHR-JFK. The first two segments are on UL; the latter two are on BA. The reason for this routing is that these were the only available award flights on the date we needed.

BA has canceled its AUH-LHR flights between ~April and October. We are traveling in early April. When I clicked on my record locator, there was a message stating that "your trip changed." Clicking on that message did nothing, but the AUH-LHR segment is now missing.

I assume that this issue will not fix itself, and I will need to call. I'd appreciate the forum's advice on how AA's obligation to rebook us interacts with what I believe is BA's "UK261" obligation to rebook us--and what airline would be best to contact first.

Getting an AUH-LHR EY flight to replace the canceled BA flight would be perfectly acceptable, but the only awards showing on AA's end include an additional segment (even in economy) and BA A320s, which I really want to avoid during a long journey.