Thank you for taking the time to create a suggestion! As an Australian I sympathise with you, but unfortunately there currently isn’t a big enough demand to maintain a region in this area, it would cost more than it’s worth. The team is always keeping track of the numbers, so if there is ever a need for it they’ll be sure to look into it. 
As you seem to have already found, this suggestion already exists here: Australian Server Region, so feel free to vote there instead.