I don't believe that Starboard would make a bad board, maybe it's better on lighter winds like the Z.
We didn't see a "revolution" about boards and sails in the last few years, and I think that's why we saw a F161 winning the worlds. Wojtek believed in a little more wind than the F162 guys expected and he won the bet.
There are lot more things to win races than just the board, I remember that Steve Allen chose the F160 last year in Fortaleza because he knows there would be a windy championship, and he wanted more control and Wojtek just did the same.
One interesting thing I notice about Wojtek, he didn't show any sponsor sticker on his gear, No Starboard sticker on sails, even the tiki stickers is gone and no other sponsor stickers.
Some F2 guys chose the F2Z hoping for lighter winds too. See the post "To Z or not to Z" by Steve Bodner in his blog:
Finally I think Wojtek would win win with the F162 anyway. He wanted to win so badly that nobody could stop him.