Brownie, they certainly used to be able to download an image of the essay (in original handwriting) when we looked into the issue a few years ago. Much has changed since then: 1) fewer schools require the essay now; 2) rSAT has made the essay optional; 3) schools allow for self-reporting during application so won’t have access to your score report (and presumably the essay as a supplemental download) if you go that route; 4) UChicago is TO so you don’t even need to report any scores at all, not even if planning to matriculate; and 5) UChicago doesn’t consider the essay (score) to be “essential” anyway, although presumably they consider it if submitted.
Despite all these changes, approximately 70% of rSAT takers opted for the essay as of 2018. Furthermore, I doubt that the majority of students are content to self-report scores on the Common Application and that colleges and universities, including UChicago, are still receiving lots of official score reports. If they receive your official score report, they should be able to view your essay unless policy has changed in the last couple of years.
The Common Data Set Section C.8 part C allows colleges to explain how they use the essay. One of the options is: “as a validity check on the application essay.” Even if that box isn’t checked - or even if the college opts not to file a CDS - I’d assume that this practice is always potentially available regarding any particular applicant’s materials. A simple way to think about it is: If you submitted it, then it’s viewable. There is nothing in UChicago’s application policy - either in letter or in spirit - that contradicts that. In fact, they imply strongly that they will look at whatever you send.