Also remember reading in an ASX statement that there were a handful of 737-800's due for delivery next year (which are to replace the 700's on lease). Maybe with the slots freeing up,
VB will convert those 800's into 900's and as there are still quite a number of airlines wanting the 800...those slots won't be too hard to fill.
VB do need the capacity on the SY-ML, SY-BN sectors during peak periods. As it stands there are flights leaving every 15 minutes for those sectors around 8am/9am and with increasing delays in/out of Sydney it does makes sense.