E-mail from Thai said:
Thank you for contacting us. Our space control in Thailand is currently working to reinstate F/C to passengers who were downgrade. Our schedule was changed at beginning of September to where all Sydney flights after Nov 1 would no longer offer First Class service. However, over this past weekend, the flights were changed back to 747 equipment with F/C seats.
Regards
THAI AIRWAYS INTERNATIONAL P.C.L