I don't think Airservices has thought this out. The proposed airspace has to include at least half the GA, RAA and SAAA aircraft fleet.
Furthermore the devil is in the detail: "Leveraging new technology" is code for mandatory ADSB out, however that requires at least a $3000+ high integrity GPS whether you want to (or are permitted to) use Class C Airspace or not.
...And you can stick the Sky Echo where there is no echo - all I see when I look at one is a future E-tag. I'll bet Airservices has a plan to charge everyone for the "privilege" of using airspace.
I do not buy the safety case for one minute either.