I wouldn't hold my breath. Nebraskans live a long time and nobody dies just because you want them to. Besides, there's no way the shares drop 30% in your scenario. A general market drop that would hurt shares of the main businesses in BRK could, but at that point there would be better ways to buy in than BRK.
The succession plan is in place the current management is adept at his style and will continue as he would. Day in and day out this is a great long term play. I've been in a long time and will not be changing anytime soon. Timing stocks is not by bag. I sleep well with BRK-B