During a recent trip to that area, I wanted to make a few changes to our itinerary. I called AA, who said no availability. I tried QF check-in agents at the airport. The same day changes were easy, the agents just typed a while and did it. A change from one day to another (SYD-AKL) took a long time. The initial answer was no, but after much conversation between me and the agent and then between the agent and her supervisor, they finally said yes. On that flight, there were two other passegners in a 25 or so seat J section.
Relevant flights were in J and I'm AA PLT. In each case we had to explicitly acknowlege that they might not have enough meals for us. Not a major price.
So there's always hope.