While I love Devolver's strange E3 conferences as much as everyone else, I don't think they are a good platform to announce games. If I'm not completely wrong, the chances are pretty high that people (me included) will remember the show but none of the games.
But who knows, publicity for their games might not even be the goal of the show, it might just be publicity for Devolver that hey can then use to promote their games. Maybe?