For the next Zelda I’d love for them to use the same engine/overworld as BotW (as it would give a quick turn-around in getting it out) but to have a completely new threat to the series - an invasion from a foreign land, for example.
There should be a more densely packed enemy presence within the world. Enemy encampments could serve as the shrines & mini-dungeons, as well as having enemy “fortresses” that would serve as classic dungeons.
New runes to be found for the Sheikah Slate, new weapons (that don’t break as easily) magic added once more (Dins Fire, Farore’s Wind, Nayru’s Love & more)... and I’d love to see Loftwings as an added method of travel in this Hyrule - with air battles too!