RF,
I'd go with exactly what you said. No new areas. They simply won't have the players to compete alone, which will mean players will need to relocated.
Brisbane should have 2 because they have the second largest base and therefore beyond non-Wallaby Reds and any Perth or Melbourne discards who come back to QLD for it, have the best ability to supplement them.
Likewise Sydney with 3 teams to make it an even 8, and them having the largest pool.
The last 3 pick themselves.
Fuck Adelaide, Fuck Newcastle, Fuck Tasmania, and fuck anywhere else where we would need to relocated players from one of those 5 locations in order to bolster (or likely provide the bulk) of numbers.
Ideally long term the ARU should be identifying how they can grow in these areas (numbers wise for the Southern States and financially for Newcastle) with the view of expanding to a 2 tier system like NZ has that would allow this in the near future though. I just don't think now is the time for them. We should be looking to consolidate a successful comp, have it financially sustainable and have all games televised. I don't believe these regions would allow for this right now.