The outdoor queue is very Disneyland-esque. Ever been to their Fantasyland? There are so many chains and queues you don't know who's going where. The Matterhorn queue is out in the open and susceptible to line jumping. Heck, Indiana Jones has an extended queue that is separated not only from the showbuilding but from the rest of the entire queue! They use the roof of the Jungle Cruise queue to hold people and then a CM ushers them to the next portion of the line in little herds.
This really isn't the worst thing it could be. At least it's not spilling out in the streets. There are fans there to cool people off, and the surrounding buildings should be able to provide some shade. Not to mention, how is it different being in a queue versus walking around? You can spend thirty minutes outside walking to IoA or thirty minutes outside waiting for a new E-ticket--the sun is hot people, but that's the price you pay for getting to go to a world-class full-year theme park.
In all honesty, the queue is one of the only things I haven't been disappointed with regarding this project.