From a gameplay perspective, yes it matters.  Wind effects fire propogation and gliding.  So being able to easily see how it is moving through dry grass for example is influencial. 

However, I would say such environmental details in sound and animation are absolutely crucial to the games aesthetic tone.  What they have shown and described is a desolate, melancholy setting atmosphere.  They want you to feel like you are wondering the ruins of a once great kingdom now overgrown.  As such, there's not as dense an NPC or animal population as in, say, Skyrim.  There are NPCs, animals, and towns (all those have been confirmed), but there's a major focus on the land and environment themselves.  What the small details like the abundance of ambient sounds and wind effects on grass and trees accomplishes is a sense of energy and life in the world without NPCs.  Most games like Skyrim use creatures and characters and other NPCs to create a lively world.  Take away those aspects and the environment is really quite static and lifeless.  Breath of the Wild, not so.  They are going for a world that feels alive and breathing even though empty.  For that purpose, those minor details of environmental interaction and motion are very important. 

I don't even know how is possible this game can run in WiiU, huge achievement right there.

And God, this game looks so good, my hype levels are insane, I have to stop watching videos about it.

Would you have believed it was possible on the PS3?

No, I don't, because it isn't, looks like is already using all resources from the hardware.

Just to remember... the "all resources" is like a myth, most games on a platform use all resources, but few use it the best way.

But yes Zelda will probably be the best use of WiiU capacities.

Most likely, seeing as it will be the last Wii U game that strives to push the platform, and is the culimination of many years of extensive experience with the hardware.

It's been a long road for Nintendo from this:

To this:

A long road but a surprisingly smooth one.  The one benefit of the Wii on visual tech for Nintendo is that it did alow them to ease in to HD and also let them get the "brown with bloom" phase out of their system before making the jump.  I mean, you look at Skyward Sword and you can definitely see they were well positioned for the jump and had figured out a lot of things others struggled on when jumping to HD (foliage, most notably).