Just got an update from CX as follows:
Following the Government’s announcement that fully vaccinated Australian citizens, permanent residents and their immediate family will be able to fly to Sydney quarantine-free, we are pleased to announce we will be offering increased capacity on our flights to/from Sydney with 10 flights a week from 1 November 2021.
Spoke to CX about the unvaccinated issue as they specifically said call and do not book online. So they have been advised by the government that unvaccinated passengers can book flights in November on any airline but depending on how early they booked, they will notify each airline to cancel passenger ticket few days prior to their flight.
I would have thought a ticket system would have been better but maybe they haven't got the time to set one up in 10 days.