First, malicious submittals are not unknown, although they are very rare. There was one rabid perp last year -- we never figured out his motive, nor the way he chose his victims. But I could count all of the incidents I've seen on the fingers of one hand. And that's in what, 60,000 edits? (Lots more common are stone-cold-brain-dead submitters, and the software developers who sell these clever programs that submit every page on your site ... daily. But it's been about a year since I saw one of those either. I think people figured out they didn't work.)
The only definite effect of such malicious submittal would be:
(1) to make sure the site really is submitted -- which isn't malicious,
(2) to make sure the site is treated last when sites are reviewed in date order, which is not the normal order anyway -- and editors don't have to follow any order. (I basically never follow a predictable order -- I just cast my eye over the list and pick an interesting-looking description, then do several sites until I hit an uninteresting one, then start over.)
(3) to keep you from asking about its status. and I've never seen a case of this confirmed. Of course, it will take awhile to see one, if there is 1 case in 20,000 (as the other statistics would suggest.) And it really isn't that big a deal -- those cases would be swamped by the 1 in 100 EDITOR error rate (again, my approximation based on a sampling of my edits and these forum posts).
You're more likely to win a hundred thousand dollar lottery ticket than to have to deal with issues like these. You're MUCH more likely to get the NIMDA worm, or have an automobile accident. You're much more likely, in fact, to die tomorrow. So ... this really isn't something to worry about.