No one here is happy about anyone losing their jobs.
I doubt very much that the closure of the Melbourne base would cause a CR.
If there was to be CR it would apply last on first off, all bases, irrespective of Melbourne base closing or not.
If more Melbourne base got CR it would only be because there are the most recent recruits down there.
In fact, if the Melbourne base did close, it would mean a slight increase in the hours required to fly for all crew as positioning to Melbourne would have to factored in, hence a slightly lesser need for redundancy