The informant, NR, is a current Boston University student and heard about this superstition from friends while walking around campus.
“So, there’s a, there’s a giant seal in the center of Marsh Plaza, which is kind of like the center of campus. And it’s superstition that like, if you step on the seal, you won’t graduate in time. Literally like, you can go to Marsh Chapel like any time during the day, and like it’s the center of campus so like it’s always going to be, there’s always going to be people walking every which way. But if you observe, you’ll, uh, notice that people will like actually go out of their way to avoid stepping on it, on the seal.”
I think this is a pretty common college superstition, and I’ve heard mention of multiple similar versions on different campuses. Many universities have school seals embedded somewhere on their grounds, and since the seal is associated through its shape with the authority of the university, stepping on the seal could be seen as disrespecting the authority of the educational institution.
Alternatively, the seal could represent the college community, and disrespecting the community by stepping on the seal would result in being left behind while your classmates graduate on time. Other versions, like the one linked below, include conversions for reversing the bad luck drawn by stepping on the seal, but the informant says he has never heard of a conversion for stepping on Boston University’s seal.
For another version of this superstition, see this superstition around stepping on the seal at Auburn University: “Auburn University – Seal Superstition” by Eli Alford, USC Digital Folklore Archives, May 1, 2021, http://folklore.usc.edu/auburn-university-seal-superstition/