User blog comment:DaNASCAT/Technical Update: April 3, 2012/@comment-4785876-20120403172823/@comment-13301-20120404093621

Thanks, Captain Obvious! But that doesn't dismiss the fact that it would never happen with normal talk pages ;) &mdash; whether the wall is optional or not. In fact, when a wiki activate the Message Wall, it's no longer optional on that wiki, since talk pages are protected.