Don't forget that a proportion of those in First and Club World, and perhaps a significant one, will be Executive Club members who took the opportunity of last year's "50% off" sale to use Miles for redemption flights.
These passengers generate very little revenue for the airline. For example, I paid slightly under £400 for each return booking from the UK to North America in Club. (Plus 50,000 Miles, of course.)
So, without knowing about the yield, load factors tell us little.