Only people who can answer that question are the people on the...

Only people who can answer that question are the people on the ground monitoring the condition of the access road.
Buru can't afford to start too early, damage the road and or finish up with a rollover.
For the sake of a few days, its better to play it safe.
Also the Great Northern Highway is still damaged and under repairs: 'Great Northern Hwy both directions Roebuck Roadhouse to Willare Roadhouse West Kimberley - Road Surface Damage'.
All is not back to normal yet.
So hopefully they start carting oil soon, but hopefully not too soon.