I was an OSU admit from the waitlist a couple of years ago (although I was on the MFA side, but I don't think the process is all that different), and I didn't know I was on the wait list for some time, maybe a couple of weeks. I do seem to remember that rejections did not come out at the same time as the acceptances, as seems to be the case this year, so everybody except the straight admits was in limbo.
Wasn't there a waitlist notification on the results board? Or am I making that up? It seems to me that if you haven't heard anything at all, there's a decent chance you're unaware that you're waitlisted. This is all speculation, of course, and I'm no longer in Columbus so I'm not at all in the know for the present round of admissions.