Does anyone know how many months in advance JAL tends to confirm aircraft allocations for routes and release seats for sale?

Trying to book PE on SYD-HND but it's not available between May and November for some reason, despite the route being flown (as currently sold) with 77W and 789 which obviously have the cabin. Even when PE is available for sale in November they're only selling W semi-flex fares. I can't imagine JL would reduce capacity by swapping in a two-class aircraft. Anyone know if there are changes afoot on the SYD route?