Okay, when I re-enable that setting, it still won’t show email address on the Admin > Users Listing Pages. It shows in the Admin User Profile and the User Profile, but I can’t do a bulk search on the User Listing pages anymore 
What I don’t know, is if that was intentional, after re-enabling the setting. We use that feature a LOT, as it is easy to identify multiple accounts, bots, etc by the patterns of their email addresses.