Clinton, if the same number of aircraft are entering BK and you have three approach points instead of two you reduce the chance of a collision.
I will say again, there will not be big changes at GAAP from this decision. When all on non radar towers go to NAS class D there will be the advantages of a simpler and more standardised system.
Also pilots being trained under what are now called GAAP procedures- a unique Australian name- will be trained for class D which is used in most other modern aviation countries.