I applied to Cornell and Upenn Regular Decision in January. I wish to report certain updates about my life to the universities.
In that case, whom do I contact exactly? And do these schools appreciate such updates, especially when admissions are due within a week or two?
Thanks for your help! 
This is futile. They are at the final stages of assembling the lists.
The Ivies report their decisions on (I believe) 27 March. That’s three day from now. All (or virtually all) admissions decisions have been made and the institutions are now completing their “logistical” processes. Be reasonable, realistically it’s simply too late to update Penn and Cornell.
@TopTier Ivy Day is the 31st this year, not the 27th. At least, that’s what all the e-mails I’ve got tell me.
It is the 31st - regardless, the most, if not all, of the decisions have been made. Only the very few are going through last reviews.
So, in a nutshell, it is wiser not to communicate to them at this stage, isn’t it?
Is the achievement significantly worthy of update?
It is too late to provide any updates. The decisions are made. Best of luck.
You’re correct, Ivy “decision day” is 31 March; here’s where I obtained the erroneous information: http://talk.collegeconfidential.com/high-school-life/1628372-quick-question-when-is-ivy-decision-day.html. Nevertheless, I stick with my advice regarding the OP’s question, it’s simply too late for updates.