Actually, I believe approval emails were supposed to start being sent by the 14th, not done. Last year they had a few "approval rounds" so that they didn't fill all of the slots at once, to allow time for quality panels that would be submitted and accepted later. But it does help to have your panel submitted sooner rather than later.
The only email I've received so far (as the co-panelist of the hopefully-returning An Intro to Memes 2.0) was an email stating that my submission had been received and that approval emails would start being sent out after February 14th.
Hope that answers at least part of your question!