When you type "We are no longer accepting questions" into the title of a new question on MSO, you get, roughly, 7,435,654,757,034 possible duplicates.
Is there no way that, when this phrase is typed, you can pop up a box that states something along the lines of, "It is very possible you're asking why your account is no longer able to post questions. Please read the following page in its entirety before asking this question."? And then you can provide the user with a link to a wiki page that answers this question. Below that, you can provide a button that states something like, "If you feel your question is unanswered by the above link, press here to post it on Meta."
The reason I say "It is very possible..." is because there may be a legitimate reason to ask it, so you don't want it insta-banned.
I'm just thinking that this is probably the most common question I've seen on MSO, and it gets heavily downvoted (as it should). It's possible that it's the only thing that prevents World Peace, in fact.
I can include a mock-up complete with a unicorn and a waffle if you need a visual interpretation.