It's not the only venue where he can do that. He can host a conference call or post a video on the forum, the only two formats he's used in the past to communicate bad news for the first time. He has never and will never use MoneyTV to describe in detail a set back to Approval. He is going to do just as Vibe said, or there will be a PR about approval before the show and then the show to announce on TV that he's got approval, which was already just announced by PR.
He would be better off doing a website video, with complete control, then open the possibility of one of those out of left field questions,which may be fumbled.
From my understanding, the FDA can't just reject an application. They can say the device is not ready for prime time yet and needs some revisions, but they can't just say "No." I think Dean touched on this before, but could be wrong.