Not 'all' domestic gates I think is the point.
Virgin have only 2 gates at each of MEL, SYD and PER that are A330 compatible (I think) - when they're full you've got to use the stairs!
http://airservicesaustralia.com/AIP/...SYAP03-138.pdf
and you'll see that there are only 4 gates at QF DOM SYD able to do A330 - 5 less than can do 767s.