"Well, Princess, we've saved the world. Now what?"
"... Let's go east."
"East? Why East?"
"Two reasons: First, I understand a certain Champion has a house somewhere to the east and second? Second... East is as good a direction as any for us to go."
"East it is."
Hyrule as their ancestors knew it (indeed, as they knew it from before the Calamity) is gone and something tells me that their civilisation is going to have to mostly start all over again from the ground up. So, why not go east? Most of the friendly races are there and... I strongly suspect that Zelda wants the opportunity to be just Zelda, not 'the Princess'.