If deferred, you are able to switch to ED2, and ik someone last-year from my school accepted ED2 to UChicago (though idk if they applied EA or not.)
IIRC UChicago tends to defer most reasonably competitive applicants instead of rejecting them, and they’re big on demonstrated interest in the sense that their yield rate is 80%, which is as high as HYPSM: they’re looking for students who really LOVE the school, and applying ED2 does show that.
As long as you can afford UChicago and you really LOVE the school (if you still love your ED school more, then see below) then apply ED2 and widely to other schools (safeties, matches, and reaches) and hope for the best!
If you don’t like your ED2 school as much, then:
"My Advice on applying ED2 after deferral ED 1:
If you do get deferred from your top choice school, I DO NOT recommend that you apply ED2 if it’s not also a school you love. From my personal experience, I was deferred from Brown ED and was planning on applying to Vanderbilt ED2 (my 2nd top choice,) but I decided against this because I still wanted to go to Brown and this year, unlike the previous, Brown deferred ~25% of the ED applicant pool vs. ~60% last year, meaning I had a higher chance.) I ended up being accepted to both Brown and Vanderbilt RD, proof FOR ME (YOUR MILEAGE MAY VARY ) that if I hadn’t waited, I would have always regretted not waiting for Brown RD. Also, I was admitted even though another student had been accepted ED already, so don’t feel discouraged that it’s not possible if that happens: you STILL have a chance, and make sure to reiterate your interest in the school (look-up what a letter of continued interest is for students deferred/waitlisted.)
HOWEVER, I was willing to wait and risk the lower chance that I wouldn’t get into either of my top choices because I had other options (safeties offering generous scholarships: APPLY TO SAFETY SCHOOLS, ESPECIALLY ONE THAT IS AFFORDABLE AND OFFERS ADMISSIONS ON A ROLLING BASIS etc.) that I would have been happy to attend if not admitted anywhere RD. At the end of the day, every applicant’s admissions journey is their own, so it’s up to you to weight the pros vs. cons of applying ED2 or waiting for RD decisions to release.
Furthermore, applying ED2 shouldn’t be used just to increase your chances of getting into a “prestigious school.” If anything, the second early round is more competitive than ED 1 given that it includes students who applied early to HYPSM etc and weren’t admitted/deferred, and want to go to another school that’s a bit lower on their list. ONLY do this if you’re extremely confident that, like with your ED1 application, you can present an application that shows you’ve done your research and would fit well at the school.
Also, this year in particular, multiple students from my school (and from YouTube videos etc.) were deferred ED 1 and ultimately accepted RD. Even for schools like the Ivies that don’t consider demonstrated interest on paper according to their admissions websites/Common Data Sets, applying ED is THE ULTIMATE form of demonstrated interest: you’re essentially telling a school that if you admit me, I’ll go, and if you’re able to show through your application (essays, letters, interview etc.) that you’ve thoroughly researched the school and are confident that THIS school and its particular resources would make you a “good fit” here; the school is more likely to accept you, given that you’ve taken more time to show interest than a student applying with rushed essays 1 hour before the deadline.
TL;DR: IMO Only apply ED 2 if you LOVE the school as much as your ED 1, can afford the school (run applicable financial aid calculators,) and can present a well thought out application by the deadline."
Hope that helps! Good luck with admissions!