Last year on checking in for QF25 MEL-AKL-LAX at the First class counter, I was advised the flight was lightly loaded and was helpfully offered a row of three down the back. It meant moving from my 21C (743) allocated seat to 61H with 61 JK blocked. She had to ring QF in AKL to ensure these seats were blocked out of NZ as well. ^

BTW, Several Middle rows (DEFG) were empty but she advised they were harder to protect.