Many of us are constantly looking for LAX-SYD availability, when the one-month chart comes up it shows only Y but you can select J, PE and/or F and try again. Then a few dates are shown but when you click on one of them it invariably seems to show only Y availability on the direct flights, as you mention.

Scroll down a page or two and you'll find the J seat, it's always on QF26 to AKL connecting to a local flight to SYD.

Up to you whether you ant to grab that seat with the intention of changing it to a direct flight nearer the time, seats are usually released 1-2 weeks ahead