Keg, I think the difference is, unlike Dubai, or London, they don't say for example - "Make Rivet at xx" which is undoable in the time frame they give. WILL ADVISE says to just say that we "can't make it" like in a heading during vectors in weather. But it is not the same, as with the heading, there is a chance the aircraft can take the heading, but with a 10min delay from 200nm, there is no chance of getting the jet to hover. So effectively it is a waste of bandwith. Like I said, Dubai, and London just put you in the hold and give you an ETA. Muscat, assign you a mach no in prep to for UAE's sequencing. Both these methods appear more effective that the way its being done in OZ.
Haugtntey- I hear you, and I get that you are not complaining about the delay.