This has been an exasperating change on a few levels. The change appeared several weeks ago and only today did I get a pop-up with an explanation and a link here. I hated it from first sight. I use vision accessibility functions wherever I can, and otherwise customize my UI as much as I can. Microsoft unfortunately does not lead the way in the Accessibility arena. Others have mentioned the wasted space of adding this new column with very little of it occupied. When using larger fonts, my email takes up a lot of space. I searched around for a way to get rid of this column and put the Calendar, Notes, etc back at the bottom of the Folder pane to no avail. So, that was a bunch of wasted time; explanations about changes should appear with the first release.
The one way I found to live with it is to minimize the folder pane. But that is not a fix; I'd rather have easy access to my folders with a resizable folder pane. I have Word and Excel pinned to my Task Bar, so I won't be pinning them in Outlook. Unless, ..... is Microsoft planning to get rid of the Task Bar??
I would hope that Microsoft employs Ease of Access users when they are designing and changing UIs. But with just skimming the comments here, it doesn't take low vision for this change to be unwanted by your users.