Some of the most successful people to come from American Idol didn't win-Jennifer Hudson is a good example. She lost on AI, but got signed for "Dreamgirls".
He still can get a recording contract, most studios don't appear to have too many problems with their substance abusing artists. Geffen was GNR's label in the 90s. Not only is Keith Richards still alive, he is also still a Rolling Stone and signed to whatever label they are under these days.