But didn't Laura (or was it Emily?) say the reason for BotW being delayed was localization issues? Perhaps the game is delayed in PAL but will be available at launch in NA and Japan. Also makes sense that Laura's info is biased toward Europe, since she is European.
Then again, everyone seems convinced of Mario being a launch title, and it's not like Nintendo to release a main Mario game alongside a Zelda game. And Mario moves more hardware units than Zelda anyway.
Even though those two leakers have proved their credibility, I just don't think they're right on this one. Last year, Miyamoto said the next Mario game was far off from release, and they've been pushing Zelda ever since e3. It's also been in development longer and clearly had a great showing. It seems like a perfect launch game for core gamers.