The prospects of French competitor DCNS (led in Australia by Sean Costello former Chief-of-Staff to former Defence Minister David Johnston) may have improved now that a hybrid or full build of the future submarine may occur in Australia.
"Anonymous" (below) speaks with authority and there are no noticeable language differences that require cleaning up.
Only one hull section (rearmost propulsion section) will require complete redesign, in order to accommodate diesels, fuel and batteries. This involves a scaling of the Scorpene propulsion module, using similar components. Hardly revolutionary stuff however. There will certainly be no arbitrary down-scaling of hull thickness, or complete redesign of 80% of the hull components.