It is possible to move a newsletter out of the newsletter namespace, which then causes all of the links to the newsletter in the newsletter Special pages to be red. If one tries to change the title of a newsletter, either in the same cross-namespace move or later, an error of "Cannot find newsletter with name <NEW NEWSLETTER NAME>" appears.
Related Gerrit Patches:
|mediawiki/extensions/Newsletter : master||Introduce stricter validation involving Newsletters' content models|
Well, in that case it wont be an issue, I guess - as currently the right to move around something in Newsletter namespace is reserved for 'Administrators', and we cannot expect them to do things lik this!