If you look at the NAS document as approved by cabinet you will see that it clearly states that we will have different cloud clearance requirements than ICAO and that Australia will notify a difference
Is there any mention about parallel runway ops?
If yes, we'll only have to make a couple more tweeks to the Class D model and the result will be something eerily simlar to GAAP.
But hey, the wheel worked, lets re-invent it.