I can see it now, Yasou's Windwall interaction with Maokai's new Ult being what people have been suggesting for seasons with Nami's ult.
Edit: Meaning it will only stop the portions touching the Wall, not the entire Maokai ult.
Ralanr1 votesWhat's the interaction?
Muzét1 votes? Didn't get it.
Shuyin1781 votesYasuo's windwall is going to stop it just like every other skillshot, so what.
The Last Ballad1 votesbut not all of it if only a portion hits. Currently, if Nami's wall hits any part of a Yas wall, even just a pixel at the very edge, the lane wide skill shot is blocked(which, considering Yas's wall also can grow to being most of a lane, is a lot of room for error, or would it be "not a lot of room for success"?) Considering it is a wall of water, you would think that a bit of wind wouldn't delete all of it if only a small amount of it was touched. Having it divided into 4 skillshots would be helpful enough, make it so that Yasuo would have to actually aim his wall to block it, instead of just throwing it so any part will collide. Realistically, it wouldn't change anything, but it would help those cases where Yasuo shoots his wall in the wrong direction and still manages to block it.
Shuyin1781 votesWe won't know until next week if it will be part or not, probably will be according to wording, but it's Riot so they'll find some way to mess with it.
PimpStickNasus1 votesHe means where with Nami ult if the yasuo wind wall touches any part of it the whole thing will be stopped where with the new maokai ult it won't all be one root so they'll get blocked individually
SwiftKitten881 voteshey... look on the bright side.. if they add this to maokai it means they have FINALLY figured out a way to properly code it... THAT is what was holding them back.
it would be stupid to try to do all the champions at once, they would want to test the code on one champion and make sure they have it working properly before adding it to other champions. and the choose 
because he was getting reworked.
quite a simple and well thought out reason really...
ModAcademy Kayn1 votesNot really... Maokai's new ult is literally 5 separate projectiles. That isn't coding, that's just making 5 different models. Nami's is a single Projectile.