About the fate of the Hero.
Zelda and Link are built to be with each other, yet they will not in any era. As soon as he Awakens, the Hero looses his prospect of settling down to family life and does not regain it even after fulfilling his assignment. This is the Hero's curse, for he is essentially a tool for the Goddess Hylia just like Ganondorf is for the Demise. (That is why Zelda in Skyward Sword regrets using Link.)
The Hero will face further adventures and often disappears on mysterious ways ere the Princess and he are able to discover their mutual feelings. (Again, Skyward Sword-Zelda foresees their future egos never growing as close together.) The process is required to circumvent the Hero being born in the line of another. Instead, he must be a pure reincarnation, an unbiased soul - to save him from insanity provoked by the Circle as well as to prevent that he realizes the hopelessness of his fate and starts to fight against it (like Ganondorf).
The harsh regulation does not pertain to the protagonist of The Wind Waker. This Link is not chosen to inherit the Hero (Princess Zelda ocarinaed him out of that timeline), but becomes one by his own ardour.
And by the time the Breath of the Wild coats the edges of alternate outcomes, divine wrestling and care, another Link may be awarded the chance…
I also imagine that Link and Zelda were born on the same day of the same month in the same year everytime.