No, the people banned prior to, um, 2009? are not permitted to be present at events hosted by U.S. Figure Skating. The relevant language was deleted when the Grievance Committee rules were changed, but it should still apply since it was in place when they were banned. This became relevant when Bob Young purchased a ticket to 2003 Nationals, following his permanent ban, and attempted to coach from the stands. I don't know why the language was deleted, if it was an oversight or if the lawyers made U.S. Figure Skating remove it. Regardless, rinks are (generally) privately owned facilities that have wide latitude to deny entry/remove individuals. If any of the coaches banned for sexual abuse appeared at a competition, the police would be called immediately. (The people banned for embezzling from their club and other such violations - they're not as well-known and might be able to get away with being present at a competition simply because no one knows what they look like.)
Bob Young, of course, has moved on to his second career: photographing aspiring young models.
(Why is there no "vomit" emoji on FSU?)