Like the government the commercial providers rely on contractors to do the aerial mapping work. It is not as simple as taking an aerial photo and overlaying it on topographic mapping, a lot of corrections need to be made..No need for the government to organise a contract for aerial photography of the Darlington area, purchasing the rights to the existing commercial satellite imagery used by Apple should be sufficient.
The area around Darlington obviously has not been flown for a long time and is obviously overdue now.
And paying to massage the images so they overlay onto the base mapping projection if it is different to Apple's. They must be geo-coded for the projection used and even adjacent images being colour corrected as well so the join is not so obvious.
It is nowhere near as simple as just dropping an aerial photo onto a base topographic map. The amount of processing, and data, involved is enormous. Fortunately a lot can be done on the fly.
Neither would just the Darlington area be flown; any aerial survey would be of the entire metropolitan area from Sellicks to Gawler.
There are companies that regularly fly aerial surveys, the frequency depending on the activity in the area being flown. One such Australian company is Nearmap.
Metro Adelaide is covered six times a year. Their coverage Australia wide is very patchy.
None of Google, Apple and Bing would guarantee either positional or temporal accuracy of the information they display, but they are interested in coverage, and, Google at least, obviously use different resolution base images depending on the scale at which the data is being viewed.
Which aerial imaging is used is, I suspect, highly influenced by cost.