That is an interesting theory actually. Somewhere along the line, Link and Zelda would have to be related if Link and Zelda marry in any game, and that is a popular ship. I think that the only three games in which Link and Zelda become a couple are Wind Waker, the original Legend of Zelda, and...
Never thought about this that much before. Until recently, I always assumed that Link didn't really have a love interest and instead just had a platonic relationship with Zelda and Saria. Yet it would make sense for him to have romantic desires like he does in what I have seen of the manga. I'm...