I could see this coming.
SF (SAS/Commando) are the dominant Aussie players in A-Stan, I bet if you asked them what they would prefer - Option A - more state of the art light deployable guns, which can be underslung and deployed to remote FOB's by Chinook (such as the M777A2), or heavy SPA, which will need to be transported on a low-loader or make its own way under escort to the FOB. I know which system I would be gunning for (excuse the pun).
I can see the SPA's being put on the back burner under the current Government.
SF aren't looking for major artillery, its not their core business, and they don't need it for the way that they fight.
arty support comes from a number of areas, getting aust arty in place just to support a SF requirement (which doesn't exist anyway) is dead money.
they're after other things - not large cal arty.
SF works on mobility, and most of the SF mission types are based on kill/capture scenarios without visible support - they rely on flight time support if pressed - not land support. If SF require metal on target to assist then thats the job of the JTACs to call it in, or if they need back up at an organic level then thats what the other taxis (air and land) and other units (Cmdo) are for.