in this video you could clearly see that when the moment he casted his windwall, the ezreal ult was quite literally ontop of him and should have hit him but... yasuo casted his windwall.
lets ignore the fact that he didn't even aim it properly because this bullshit windwall works like a 360 degrees all-around protection from everything
because the way it forms is from his center of the champion and moves outwards. basically gives him complete safety from every angle for the first few moments.
make it form directly infront of him at a fixed distance from him.
it will make it so projectiles that have actually passed that fixed distance would infact hit yasuo.
it would punish him for reacting slow and for missing the windwall's direction, because right now there is 0 punishment for it.