Pretty sure this submission has been posted before (and rejected). I expect that it could cause issues in worlds that have hundreds (and thousands) of pages—while those worlds may well be a minority, I think that potential for trouble is enough that this shouldn't be an option. Just go through your categories one at a time if you need to check something on every single article in your world.
A page of all articles in a single list without any folders/categories/etc, so you can see everything at once would be very useful when I'm going through and updating a bit of common formatting between everything - I can just go down the list easily.
Amen! Include option to print the list