Having a scheduled appointment for renewal or initial GE membership “interview” doesn’t prevent the ability of the conditionally-approved (renewal or new) applicant of using the enrollment on arrival path prior to the scheduled appointment date.

For ORD GE enrollment on arrival, renewal and initial GE applicants are handled at the same area — as is common at relevant airports for enrollment on arrival — and the length of the wait in terms of number of applicants and time for applicants to be processed can vary. And at ORD too — especially if having to make a relatively tight connection for flights departing from Terminals 1/2/3 — the lines for enrollment on arrival may be such that a GE renewal applicant able to use GE may want to skip the enrollment on arrival service and do it on a different day. ORD used to have very limited hours for enrollment on arrival but they seem to be doing enrollment on arrival over longer hours than used to be applicable.