A philosopher elsewhere writes:
Does it ever make sense for a department to invite waitlisted prospective graduate students to visit?
I am aware of a department that invites all accepted and waitlisted students to visit, offering to pay for the accepted students' travel but not for the waitlisted students'. On the one hand, this gives the waitlisted students an opportunity to make a more informed decision, which can benefit both the student and the department. On the other hand, it risks a host of logistical complications and social tensions during the visits (both because waitlisted students might feel awkward being around accepted students and vice versa, and because the waitlisted students may feel the need to perform—or worse, compete—in hopes of improving their standing), and it may even make waitlisted students feel that their best chance at admission is to visit, even if doing so is financially perilous.
I know of other disciplines that invite waitlisted students, but they pay for them to visit. Inviting waitlisted students to admission events without paying for them is perverse and exploitative in the way my correspondent worries. Comments are open: please use a real email (which will not appear), and in your comment indicate your position in the academy (e.g., philosophy professor, graduate student, professor in phyics, etc.).