Yes; you are correct. What California statistics are really saying is that the ones that are leaving in droves are middle class on the whole . . . which means a massive loss in both tax base and general circulation of money within the state.
Illegals are probably easily replacing those numbers, but NOT in circulating income. But since leftists don't want to admit that serious wage earners are outright worth more than economic parasites, they are ignoring the poverty stricken incomers and their additional drain on the state economy.