The Master Sword seems to be in a bad shape in Breath of the Wild. Let's hope that it doesn't break, because we all know, where this will end:
NO DIN!! Please, noooo!! NO! Noooooooooo~~~~~~!!!
(Yes, it's actually possible to have the Master Sword broken in a Linked Game of Oracle of Ages. Both sword upgrades are available right after Level 4. If you do the linked Quest first, you get the Noble Sword from Farore and the Broken Sword from the Zora Elder, which then will become the Master Sword after the repair "ceremony". Try it out.)