Guys the exemption isn't as complicated as it sounds. You just need to understand how to read CASA crap.
Current rules state: Ratio of 1:36 for aircraft with a capacity under 215.
Exemption: Ignore the crew ratio,
VB can crew a 737-800 with 4 crew up to a capacity of 189 passengers.
There is no change for crew in terms of safety procedures, but as Sinala has mentioned, there is a change in terms of workload for the service and the access to breaks during flight.
The other note in referencing the instrument and the explanatory note is that they have a requirement for a crew member at each floor level exit. Thus when the CAO actually changes within the next year or so, CASA could maintain this requirement and as such the -300 or -700 will still need 4 crew.