Because it answers the question of the status of the site submission.
You can be told that it's awaiting review, that it's been added, that it's been rejected. But nobody can foretell the future actions of a another volunteer editor and tell you when it's going to be reviewed. Even if you ask about a site in a category I edit in, I might have an estimate in my own mind about when I might get around to working on a site there, but I could be totally wrong, my priorities might change, I might stop editing for a while, anything might happen. I could not possibly tell you when I would add a site to the directory, for after I look at it it might need further thought and get put back in the heap.
If I can't answer for the categories I work on, how can another editor read my mind