On Sunday 26 May, QF73, the 1740 hours SYD - SFO and the return QF74 Sunday from SFO back to SYD B744 have been cancelled. As I'd not looked this flight up previously, I don't know if it's a sudden cancellation ex Sydney.
If any AFFers were booked on these flights, please let us know about rerouting, any STPC (QF complimentary) hotel stays, transfers, meal arrangements and how it was handled.
There is a B789 operating tonight's QF49, the 2055 hours MEL to SFO so if there were spare seats and QF could also find seats on a suitable connecting flight from SYD down to MEL, that might be one option to minimise delays to travellers.
HA452, the 2140 hours SYD - HNL connecting to HA12 from HNL to SFO would give a 2130 hours arrival in the latter. These flights are A332s.
One problem is that most USA-bound flights depart Oz in the morning (or in the case of QF7, lunchtime) so there aren't a huge number of choices at say 1600 or 1700 of an afternoon ex SYD.