That's impressively cynical, but Musk obviously stands to gain a lot if people keep California using roads. California wants to go green and he sells the best technology for green road-based transportation.
I'm not sure it really affects his electronic car business one way or the other. Firstly, he isn't necessarily selling Tesla's to people for commuting between SF and LA, that's well outside his range, and as fast as the supercharging is, it loses out to regular gasoline refilling. Secondly, I'm not sure the amount of people potentially served by the hyperloop is more than a blip in the sales charts for even a regular car company (as deciding factors for car purchasing decisions, it seems relatively low to me).
Reminds me of when an actual AI expert pointed out that by making dire predictions about smart AI, that we are nowhere near having, keeps eyes off the autopilot system and the issues with that.