I am wondering the same question.
But my assessment via Wikipedia would be, remember it will arrive in 2018 and the 777X isn’t expected to show up until 2020 and by slipping in the A330neo in 2017 Airbus may have something going for them. Andthe A330neo -900 is apparently ~310 seats which is larger than both 787 – 800/900 ( of course this changes all the time ). this means you might not have the range of a 787-9/10 but you do have a booming Asian market and the opportunity to offer an efficient product that is probably much cheaper to develop that will be quickly on the market and is potentially available to customers who missed 787 slots.
One similar example might be Toyota and their 4x4 range Rav 4 , Kluger, Prado, Landcrusier and the various version of each which I am sure have crossover in some areas but it seems to work for Toyota.