If SQ prices their fares cheaper, this QF ADL - DEL linkage flight won't last too long, probably shorter than envisaged.
Some will go with fares only, the lower the fares, that is the one they will go for, or fly with.
The flight might only be good for Aussie exports to that part of Asia, seeing that its direct to DEL SQ still has to stop in SIN, and EK not flying to ADL, QR still has to go via DOH.