MUFC Fan, it sounds in principle like a good idea but in a recession, there premium cabin volume has fallen off a cliff do you really think airlines are looking to increase their exposure to risk in this area.
Getting LCY-JFK using A318 would be bad enough to get wrong, but a 777ER all the way to Oz, it's enough to take an airline down within 6 weeks. It may be something both BA/QF will look at in the future but at the moment all airlines are looking to reduce exposure to risk in premium.