So what would wind really do? Not much, it would be something that would mainly give atmosphere to the game, which would be a great addition to the Wild Update, wind would make leaves that are floating (have an air block below it), will produce a "Falling leaf" particle, it could also affect the tumbleweeds we saw in the Badlands Biome Vote
Sandstorms could also be a great addition to the deserts, making them more interesting. Sandstorms would obstruct the players vision by a lot (basically as much as the blindness effect) and would slightly push the player in a certain direction.
The wind compass would be a device similar to the standard compass, that would point the direction of the wind could be crafted with 4 iron on each side and a stick on the middle. I haven't tought in why knowing the direction of the wind would be important, but it could affect specific blocks or mobs, possibly even a new redstone related block!
This is an idea that I'm certainly not the first to think of but I think it would be amazing to have in the game, it wouldn't affect the gameplay much, but it would give more atmosphere to the game!