It is correct . As per https://www.qantas.com/fflyer/dyn/fl...ine-earning#mh

Flights between Australia and Malaysia in business class ( or 1st class should MH introduce it to Australia ) ( ACDFIJZ ) earn as Flexible Economy

Flights booked in C, D, I , J and Z class will earn at Flexible Economy Frequent Flyer Earn Category, however will receive Malaysia Airlines Business Class service, and flights booked in A and F class will earn at Flexible Economy Frequent Flyer Earn Category, however will receive Malaysia Airlines First Class service

Flexible Economy from KUL-SYD earns 4000 points plus 30 SCs
Business from CMB-KUL earns 2,500 points and 80SCs

So total earning is 6500 points and 110 SCs

There is no status bonuses for travel on MH, so points earning will be 6500 points regardless of whether bronze, silver, gold, platinum or platinum one status is held