What I think they'd need to do. I'd like a more narrative driven game that aids itself to exploration. Weapon durability, I liked it well enough in, but they should go with a method that makes your weapons a little more personal, longer weapon durability, repair options for broken weapons. More playstyles and combat options, quests to get more techniques like the wons you learned in TP. Return to a Majora's Mask style of more personal sidequests. Also, raise the stakes, in BotW the fun came from mastering the world itself, which encourages exploration. Majora's Mask for example totally encouraged exploration, but their was always the fact that the Moon was hanging right there waiting to destroy everything. That's what I want, an atmosphere where your reminded of impending doom. Make the map size smaller to keep things tight, like %50 the map of BotW would be good.
That's my idea for a better story driven Zelda game, but the Zelda team always does what it wants either way, they might think up something completely different than what's happened before. Like a Zelda game where the Link's a career dungeon crawler and the entire land of Hyrule has an economy based off of dungeon crawling or whatever unorthodox world they come up with to justify a new gameplay mechanic.