Probably crew rest requirements rather than aircraft related. Yesterday’s QF1 delay will mean they have they a crew out of position. The crew due to operate tonight’s QF2 were probably the crew who were delayed 24 hours on QF1And tomorrow's (Sunday 01 October) QF82, which was supposed to leave at 8.30pm, has been pushed back by more than 12 hours to 9am on Monday morning. Not sure why as the aircraft arrived into Singapore this evening and would have had a more than 24 hour layover.