Not sure about why the Aussies need to buy a carrier when they could fly F-35B off the new Canberra class LHD which handily come with a ski jump.
Likewise the Japanese could fly F-35B from the Hyuga class 'Through deck destroyers'.
Both are already in the programme and could add the B to their slated purchase of A's to go down the mixed fleet route like the Italians.
It also fits with the re-focus of US eyes on the Pacific and adds backup to the USMC B purchase.
Just thoughts....