Never say never.
When I was a JO, one of our DHs was a 1st tour MP, did ROTC shore tour, then did a pain tour on a boat (I think mini on a Gator). If you look at recent selection rates and the trend line, if someone can cross the threshold to O-4 they are almost a have-to-select for DH at this point. Even in helo land we had bottom feeders with non-production shore tours pick up DH this last board.
Exactly. Pretty soon there won't be enough careers to kill.