There was talk that the share price already reflects a howard (less) SIRIUS.
They predict that if he does indeed leave that only 2 million subscribers will follow. Not sure I believe that low number. I was thinking around 10 million would leave.
If the PPS is already calculated for not resigning Howard, and if the estimates are correct for lost subscribers, then the price should remain steady.
I would have to assume that if he did not resign, the price would drop, but most likely recover based on the balance sheet.