Makes sense, I have had the vent visors on my 2006 since I got it and am used to it, but definitely know what you are talking about. I have adapted to make sure I look around the A pillar dramatically to make sure there is not a car or person. I have had a close call or two myself.The vent visor has been the documented "contributing factor" in several collisions. I personally have nearly had one myself, and I removed them shortly thereafter.
They widen the "A pillar" (the pillar beside the windshield) mainly on the drivers side. The "A pillar" is already wide on these trucks, but when the Vent Visor is added to it, it makes it wide enough that it totally blocks the visibility of an oncoming vehicle in an intersection. That's where I nearly had a head-on myself that would have been my fault.
I'm not necessarily downing the Vent Visor. They're nice, and a good idea. I've just had the Poo scared out of me and don't think the benefit is worth the risk. (Plus the other driver calling me an *%#hole for nearly hitting them head-on doesn't help things)
When I test drove the 2017 I didn't really pay attention to the width of the A pillars. They may be thinner than on the older trucks. If so, I may reconsider.