BA 191, LHR - AUS, £419, May 8th, 2022. WTP > CW

After clearing the horrendous T3 connection security, I had 20 minutes to board and took some time to stand in line to talk to the guy at the connection desk where he quoted this. I took it, was a great deal.

Not sure if this is answered anywhere, but what class fare do these promotional upgrades book into? Does anyone know?