@ucbalumnus: That’s because there is no threshold GPA for UE’s. The threshold would depend on how many UE majors apply to an engineering major, what their GPA is, and how many slots are allotted for UE’s. Two of those are unknown for every cohort.
But evidently UIUC allots enough where almost all UE’s (and pretty much all of the strong UE students) get their first-choice major.