The old OCTA rules governing the passing of traffic were complicated by the full-reporting used by a lot of VFR flights. I recall lots of traffic having to be passed and I believe each pilot also had to acknowledge that the traffic message had been received.
Post FS the Class E requirements were different, and as far as I am aware ATC passes IFR / IFR traffic information in accordance with the N of 65S rule dictated by the Minister In the AAPS.
PS. Alphacentuari - Not sure about a newly released AAPS, the current one <https://www.legislation.gov.au/Details/F2018L01386> (two months out of date) is still linked on the CASA, DIRD and FRLI web sites.
Perhaps you guys in CASA have seen the new one already?