There are some people who only have the 'student worker' affiliation and therefore do not appear in the directory. One example is a student at UNO who is a UNL student worker in extension.
The 'student worker' role was added in 52f4efe but backed out. That simple change by itself will expose their personal email for their user. Needs additional modification to treat a student worker the same as a student and hide contact info on the anon public view.