Doubt it
I know the airline industry is in turbulence but remember that Jetstar is the big performer of the Qantas group at present. They may cancel some of their orders but with the likes of Air Asia and middle east airlines taking away market share on the europe route, why would they forgo 787's at a time when budget carriers are doing well and have the potential to claw back market share?
Also lets not forget Jetstar are in Singapore and Vietnam. Nothing to stop Qantas group from switching aircraft to these markets.