Correct. WA's Transport Coordination Act requires that airlines operating RPT services (as defined by that act, not CASA) have to have an aircraft license from the Minister for Transport.
You are aware, no doubt, that both state and commonwealth governments have enacted legislation LATER found to be unconstitutional or at best an over reach.
Like I said until it is challenged, we do not know. Just because a state government writes laws for themselves to regulate aviation, a federal responsibility, does not make them legally sound or unassailable.