Why are you editing every one of the thousands of photos you take instead of picking the best ones and focusing on editing those?
And if the answer is that you do do that, then I would ask if you're only editing your best photos, why aren't you taking a moment to re-evaluate and adjust the white balance on each one once you're in front of a computer and can see them on a big screen?
And, what conditions are you shooting under that AWB is that wildly incorrect?
I often take 5000 photos at a 12-14 hour wedding. I edit well over a 1000. I understand your point of view but, like many pro wedding photographers, I take a lot and edit a lot. I understand there are really good pros that take a very limited amount as well. Just a difference in style and workflow. I make sure the edited photos are creative, unique, and beautiful. It is not like I am delivering 15 photos of the exact same thing.
AWB is often way off. In mixed light it is very easy to trick the camera into giving you a terrible WB. Churches often have terrible light. Even when auto is close, it is never exactly the way I prefer. I often like my images to be warmer.
Getting the image as close to finished in camera is by far the best option for me.
I guess I would be fine with the removal of the bar as long as they have another dial or control to adjust the WB like I do with the bar. Currently changing the WB on my 5d4 is a several step process and I would hate to return to that.