Thank-you for that advice re MCOL/AESA. The flight (VY8944) was booked for Sunday evening 24 Sep 23 and after arriving at ORY I was told that the flight was cancelled (no reason given) and that I could choose between the next available flight [Tue 26th evening] or a refund. I agreed to a refund (didn't see any fine print waiving rights to compensation), paid for an Uber to CDG, paid for a hotel, and used Avios for a morning BA flight back to London on the 25th.