Before the 380s can come back, they'll need to train about 65 Captains. They'll have to come from somewhere, so there's a ripple effect. If they said "go" right now, I still think it would take about 12 months to actually get things to more or less normal. I expect that most of the 380 training department also took the VR, so you'll need to replace them first.
As it happens, of the over 800 (I recall) 'jobs' that allow exemption to the international border closure - flight attendants & pilots are listed despite ample numbers of Australian citizens being stood down by all the airlines.I've lost track of the airlines that have officially stopped flying A380s, but presumably there would be a number of crew from those airlines that could be recruited by QF, sooner rather than later?
If so, would their training over to QF operations be quicker than training QF crew from other aircraft?