I only watch him on Fridays, but he's been doing this for awhile. He emphatically and repeatedly says he doesn't want people to buy AH the second he mentions a stock, because they'll get a better price the next day.
That would help avoid things I've seen like his recommendations moving large cap stocks up 1% AH. Would definitely reduce the appeal of the show among people who consider it a real-time trading chatroom. Now, about that show that follows his where callers excitedly ask "experts" to "help make me some fast money"...