Fubaar
I wonder why BA feel the need to look as far afield as CX? If the Brit charter airline pilots repeat their valiant efforts with the same alacrity as they did in tearing off to Oz in 1989 without even attempting to hide their utter glee to be screwing the careers of fellow pilots, they'll be positively tripping over themselves to do the same to 'mere' cabin crew.
The problem is getting 3-class aircraft. Those are almost exclusively in major airline fleets (or stored, which makes it uneconimical to re-active for short period only). Charter and ACMI airlines only have 1-class charter configs, some have 2-class with a small number of old-style C-class seats. So it is quite understandable BA is looking to get some other majors to operate at least most lucrative routes.
Anyway one aircraft cannot cover daily LHR-HKG-LHR, so there will be some lottery for those who paid 5-10k quid for their C or F tickets.