Thank you for the replies.
During my proactive phase I did investigate cancelling without penalty (the MPC had agreed I could) and rebooking as the CX website showed (and still shows) flights via the East Coast available for the same amount of miles as my original direct booking (30k). Unfortunately when you click through on all the options the miles required jumps to 70k. The same thing happened when the MPC rep tried it so she suggested waiting to see what QF would rebook me on - which brings us back to today.
At this stage I don’t feel inclined to part with that many points so I will give CX some more time to respond along with trying the suggestion in the first reply. I don’t consider CX the ‘villain’ in this situation and the conspiracy theorist in me thinks QF have offered the JQ flight in the hope that people like me will cancel and they won’t have to re-accommodate us via the East Coast.