AFAIK Class D airspace = non-radar. Don't know about other places, but at Bankstown the tower has a radar feed but it is slightly delayed and cannot be used for separation. No safety gain.
Of course with non-radar control zones come Departure Reports, plus the requirements to advise tower when maintaining assigned levels. So increased pilot workload in what is already a high traffic environment where they should not be distracted from looking for other traffic. Safety reduction.
Inbound reporting points are still used and important. The restrictions on aircraft per controller mean that we're going to have more pilots told "Remain outside Class D airspace" than before. So now there'll be more aircraft orbiting at inbound reporting points awaiting clearance. Safety reduction.
Can't find it just now, but someone said that helicopters use different inbound points at Bankstown. Not true. ERSA requires them to use the same reporting points as aeroplanes. It's just that they are then directed to track via helicopter waypoints after calling inbound at 2RN and Prospect (Of course, heli's inbound from R405 will usually use Olympic Park because it makes sense, but it isn't a published procedure)
The lack of any mention of helicopters or three-runway operations in the directives suggests to me that these documents have been published without any significant internal or external consultation. You'd only have to show the draft to any flight school at Bankstown or Camden to get reminded about that !
Ando1Bar, Special VFR is still available in Class D. Same requirements as GAAP zones and Class C.
I'd still like to think this is more about CASA putting pressure on Airservices to sort out their staffing levels and service delivery so that flight safety is increased eventually, rather than any direct policy to increase safety.
A less charitable interpretation, would be that John McCormick is under pressure to be seen to be doing something, anything. If there is a belief that this action could directly increase overall aviation safety, then it might suggest that Mr McCormick does not have an operational understanding of how GAAP zones work in practice; There is nothing in his published bio
(CASA's Director) which would contradict that.