Kincella the current commodity prices amd tax regime simply won't support new mines and some existing mines will close. Jobs are being lost now and that will increase by the time the new year starts IMO. Most of the jobs are in starting up and construction not in actual production so as existing projects Finnish up or are shut down those jobs are gone and are not being replaced.
Mining has driven the boom in Perth and its now in reverse gear there is nothing that can fill the void especially if migration slows.
I really doubt smithy will regret his move in a couple of years.