According to Kotaku, NDA's for Mario 3D Land and Kid Icarus basically forbid them from talking about the second half of those games.

It's the 4th of October, the reviews come in, and all of them are overwhelmingly positive, yet, for some reason, nothing they talk about stands out as deserving a great score beyond the updates we know of. They then tease that there's something for old fans, particularly those who grew up in the 00s...

It's October 12th, you have just beaten the E4 Champion. You watch the credits roll. The game begins with you at a dock, where a sailor greets you. "Ready to journey to your next Pokemon adventure?" he asks. Your face turns pale. Could...could it be? You slowly get on the ship, as an excruciatingly long cut-scene begins as you travel far, far across the sea...