[Cynicism]Current CAS retires in July. Current govt will not want either the Chief of the Air Staff or the FSL & Chief of the Naval staff resigning over this issue, so will - surely - just put off the decision until the new CAS arrives in post.
Torpy cannot resign when he's retired, ergo any decision to continue with FAA GR9s will be delayed until he's gone; if no announcement is made within a few days of his departure, it means Torpy has won the argument and it'll be announced that NSW will disband and its assets be handed to the RAF shortly after the new FSL/CNS is appointed. No resignations at all that way, and no embarassment to the govt. [\Cynicism]
Of course, since Hutton appears to have a degree of intestinal fortitude not present in his two immediate predecessors, he might not play that sort of Yes, Prime Minister-ish game...