VFU should concern the content of the article. You can't decide whether the article was right- or wrongfully deleted without actually looking at it. And additional evidence that a subject is worth an article that was not discussed in the AFD should be reason to rethink the initial deletion debate.
As I said it before. An AFD closure may be totally correct at the time, but VFU also concerns articles when situations have changed. "The Jar" webcomic is a good example. It was deleted for lack of notability because no one could find any information to verify the info in the article.
If someone comes in with information from the Wayback Machine Internet archive showing it was a popular comic when it was still active that should b enough info to argue an undeletion even when the AFD was correctly closed at the time.
I think VFU should be used to reconsider deletions when certain important info was not included in the final judgement. That's why the justification is so important.
--Mgm