I do find BA's attitude on last minute bookings/changes a little odd.
I changed my flight back from LUX today to the earlier flight, so I was keeping an eye on loads. As from yesterday, the only Y tickets on sale were in full Y - nothing else. As I had a semi flex ticket that didn't matter - however it meant anyone wanting to change a more restricted ticket - or in fact buy a new one - would have had to pay a small fortune. (Would have been cheaper to buy a CE ticket).
The flight itself was 2/3rds empty on a 319. The rear of the plane was totally deserted - I was in row 8 on my own. Does make me wonder why they zero'd out all the fare buckets except Y 36 hours before the flight.