"if you complete this internship and build up the required flight hours you will be put at the top of their candidate pool."

Have him give you a list of former interns that got hired at UPS or something in writing from UPS to back up his claims. I've never heard of special treatment for former interns. I wouldn't think being a former intern would be anything more than a positive subject to speak of at the interview, nor do I think it will help you skip any of the other steps to get on at UPS.