Wondering the likelihood of being taken off the deferred list? Is there a % that comes off the list or depends on regular admission rate?
unfortunately, very small 
I can’t give you any statistics on UPenn, but MIT, for example, admits just 4% of deferred applicants. Basically they saw your application and weren’t wowed enough to accept you this round, so unless you really do something amazing between now and then (which, for most people, is quite unlikely), then you’ll probably end up waitlisted or rejected.
At this point it’s best to move on. I know UPenn was probably your top choice and the uncertainty of deferral sucks (just happened to me too), I’d focus your energy on perfecting your applications for your other top choices. Remember, there are tons of schools out there where you can have a great education, and when you’re in college you probably won’t be able to imagine yourself anywhere else.
I disagree with @ripinpeace. I mean, I agree with remembering that there are tons of places out there with great opportunities, but I disagree about the chances.
First, your chances of getting in after being deferred are several percentage points higher than if you’d applied RD to UPenn. So right there your chances are higher.
Second, if Wharton continues to be your top choice, say so. Email them updates without being too obnoxious of course. I very much disagree the updates have to be stellar. They can be anything. It doesn’t have to be splashy. Got a job flipping burgers? Say so. Became manager of the basketball team? Say so. Is there anything else you can do you didn’t do earlier? For instance, UPenn offers some terrific online courses for no cost. Maybe you can take one. I guess I’d save a few such updates, then include them all together and send a strong email thanking them for their considering and then expressing how much you love the school, and specifically why–be specific. Look at their curriculum, classes, specific opportunities.
Ultimately, yes, there are many many amazing schools out there. But your question wasn’t that. It was what kind of a chance do you have. While that is not knowable, it is statistically higher than RD chances.
Indeed, in an interview, Dean of Admissions Furda stated this outright: “Acceptance rates for deferred early applicants are typically a few percentage points higher than overall regular decision acceptance rates.”
@connections when you say “your chances of getting in after being deferred are several percentage points higher than if you’d applied RD to UPenn. So right there your chances are higher”, where are you getting your statistics from?
I mean i’m not saying all hope is lost but I’ve only ever heard that deferred applicants have a LOWER acceptance rate than RD applicants
oh just kidding i just reread your comment
There was an article linked in last year’s threads on this. Yes, it is higher than regular RD, and yes, the odds are still low. I’d continue to provide updates and work my tail off to make the application stronger than it was when it was first reviewed. I’d also make sure I had some genuine enthusiasm for other schools on my list in case it didn’t work out.
What do you mean by saying “continuing to provide updates”? I believe deferred students are only allowed one update submission.
Penn will not wait-list any deferred student.
Gather all your new accomplishments into one submission to update your file. But at most schools, you can reach out to your adcom to let them know of other things post deadline. Clearly, you’re not going to do this with great frequency, but if you win something of substance after the deadline and before decisions, you want to let them know.
Penn accepted 14% of its deferrals last year (as per the FAQ for deferred applicants). That number is more than double the regular decision acceptance rate.
On a side note, if you take into account legacies/athletes/connection-based acceptances, the ED acceptance rate would probably be a significant amount lower than 22%.
To summarize all of the comments, the chance of admission after deferral is not good, but probably better than most applicants think it is.