<p>You certainly can send things, just as any student can send supplementary materials. I understand it's not exactly the same thing, but aside from something such as a midyear report that you might be required to add to your app, I would imagine your new info would be treated similarly. How much the school will take these into account, I don't know. I would imagine it would depend on the school.
I agree that generally a deferral almost always equals a rejection...but I do know this isn't true 100% of the time. So if the college that deferred you remains your #1 choice, do what you can to better you chances.</p>