Thanks for the information. I have resigned myself to checking with BA
in BKK or HKG as to whether the seats are available.

AFAIK the onboard upgrade is theoretically still available.
But you only collect the mileage and status points from the WT boarding pass
And the differences would push my wife to the QF silver level for the year.
And it is her arthritis that instigated the potential spending of the money
for a bit of comfort on what will be the second longest leg of the trip

I did note that BA does not code share the WT+ seats with QF