Quote: "Given the proximity to Christmas I'd be suspicious that some of these were quietly planned so that less seats were deliberately left empty."
Ah, wrong. All the flights are full.......if they are empty, a diversion to AKL (even with stronger wind) is not required. The costs to divert are very high, they don't it if they can avoid it.
Remember, a lot of people catch the QF8 from other flights, so with the cold weather particularly in the north, it is a lottery to see how many make it to DFW in time.