Yes, the policy had been for a very long time to have controlled fires that burned sections of the forests creating natural firebreaks with no fuel so that any fires hit those and slow/stop and can be controlled from there. It helps to protects properties etc.
And since it was done each year they could rotate the sections burned so no one section died. Our forests handle low intensity bush fires. So with no large build up of dead undergrowth, and doing it in early spring during the cooler weather the fires were low intensity, and kept small and controlled.
But for a decade or so there has been none done because they claimed it killed wildlife too much, but with the low intensity there was little of that too since the fires were very slow moving during the cooler months.
That is why the intensity was so large, its Australia, fires happen even with the controlled burnoffs, but rarely too big too handle. Ash Wednesday in South Australia was one exception a few decades ago. Our Eucalyptus tree has its sap burn at higher intensities than petrol, so you can imagine that once the bush fire exceeds a certain level the bush virtually explodes in very high intensity fires. Its almost instant death if you are caught near those.