If you go by the reasoning they used to go after solar users, they'd probably find a way to tax you whereever you went. After all, shouldn't everyone shoulder the cost? If there a difference if you opt-out by going solar or if you opt-out by moving? Heck, maybe they'll even come up with a law to stop people from leaving CA. After all, they need the money!
More likely, they'll come up with a "leaving town tax", like Springfield's Mayor Quimby came up with following the filming of Radioactive Man.