"Methinks that one factor in planning this is to get some of their European traffic back"
but that's their own fault - no-one forced them to cut a deal with EK and reduce their long-haul flights - it was the economics that did it
Flying a few pax LHR-Perth is unlikely to make them any serious return at all
TBH I can see them cutting even more of their international network if & when the oil price goes up again