I know wind will play a role mostly in the DLC of Helicopters and DLC Marksmen, since there are already many wind mods/addons scripts that affect ballistics. Still wind is something that gives life to a world.
I believe BIS should add some graphical module so u can have wind appear; maybe add dust effect similar to the default one that vehicles and people produce when they walk in certain areas; the rain should change its visuals too just by changing the existing visual corner.
The most important: a sound effect based on wind, the wind is lifeless right now you don't even understand it's existence. Even if the wind is in full there is no actual visual or audio representation of it in the game.
I believe its easy to implement and it will rise the immersion.
The low and unrealistic sound effect of the wind right now is just a stereo sample that turns around with you :(