To me it is an obvious answer.
It has nothing to do with Simon not believing in next years ski, it is more to do with the fact that he knows his old ski so well.  It has been the same for the past two seasons so he knows it better than he knows this new ski that he may have ridden only a handful of times...
If I was boosting 34-36 foot out of a quarter I would want to know exactly how the ski under me is going to react to spinning/grabbing/landing.
It's the same with the JOSS, i would not want to hit a 35m stepdown (and kill it) along with the other features on a ski that i am still not 100% comfortable with...
Having ridden next years Dumont i know that it is a ski that absolutely kills it, with a much better flex pattern to it, compared to this years somewhat soggy tail.
Either way, whatever he was skiing on, he is absolutely owning that quarter pipe and i believe he was the best rider at JOSS, from the updates he was riding the hardest and riding the cleanest, he is on top of his game right now. Props
Maybe?