On the subject of volume vs yield, short-haul Band 1-3 flights were declassified to a one class EuroTraveller configuration on (I think) 23-24 December to accommodate displaced pax due to cancellations. That's a lot of money to be paid to premium pax for refunds and downgrade compensation.
Also, BA cancelled many of its own CDG and GVA services, some on the same day it was operating widebodies on these routes.