No, it's purely down to the dynamics of fleet numbers and scheduling...
Okay, let me see if I can explain this.
When V Australia started they ordered 7 triplers with 6 options. Who knows what the grand plan was, but they initially started Daily Syd. Soon after Bne and Melbourne started as the new aircraft arrived. Pretty soon it became clear that daily Mel and Bne was not going to be an option because the loads were crap on the services that were already being operated. Management then looked at other options such as Phuket, Fiji, Jo'burg etc to utilize the 5 aircraft that we had. Those routes were still delivering operating losses.
JB arrived and quickly rationalised, cut the Jo'burg, phuket and fiji and initiated AUH in an attempt to stop the bleeding. At this stage there were still 5 777's in service and two firm 777 orders. Had daily services from Bne or Mel been viable, they would have taken those aircraft and started operating them, but there was not the confidence daily services ex Bne and Mel would be profitable.
The decision was made to defer or cancel those orders (not sure which) and wait to see if yields and passenger loads would improve on existing services. Additionally, domestic was a basket case and as that was the major contributor to bottom line, the management needed to focus on that side of the business rather than waste time on what was believed to be a lost cause (V Australia). All they wanted was for international not to lose too much money.
So yes, the current schedule is a product of the amount of aircraft and fleet dynamics, but that is a result of a management decision to restrict the fleet size to 5 aircraft until they have the confidence to start additional frequencies. That time may well be approaching, but now there are A330's in the mix as well and Virgin does not have a large appetite for rapid growth, so i would suggest that if the Company is looking at deploying the A330's internationally, they will probably get that up and running and evaluate before they take delivery of any more 777's.
The caveat on that is if EY ask Virgin to operate more services to AUH from the East Coast. If that is on the horizon, then more 777's will be required because there is not another aircraft on the planet that will fly from the East Coast of Australia to either LA or AUH as efficiently as a 777-300ER.