I don't think he'd have an interest in doing that. Why when he can just pick any dog coin and pump that.
If he were to start a coin (not saying he would), I'd assume it'd be on the same premise that a lot of newcomers try for: innovation.
Like him or hate him, he has been an innovator and a leader across multiple markets. I feel like him starting a coin would be in conjunction with services aimed to do X, Y, or XYZ better than services that are currently out there. The success of the coin wouldn't necessarily rely on the success of the services, because...hype and bandwagon....but that's another story.