No. But they regard most company information as 'commercially sensitive', including vacancy details, so I doubt you'd have got much more in the way of useful information even appealing to a senior source.

From observation I can tell you that the answer is "less than 24 hours between placing and withdrawal of ad; generally less than three days after application/test return for an offer", but it's not authoritative or (possibly) all that accurate given that I can only go on my own experience and what's reported back to me from others.