I can say pretty much 100% it will stay 777 300ER, how can the possibly send a 77W in in the morning and have an A332 going out an hour and half later??? But this has happened twice before, the end of last year and February this year were down as being an A330 but it has always simply been a system error on the EK website and it's been updated back to the 77W.
Also, OT but the A330's will still be around for a while, the A343's were supposed to have been long gone about 18 months ago and they're still with them.
Martin