General Discussion

Yes, with the recent change to California tax law, they pay taxes based on the percentage of their sales in California. If 20% of sales are here, then CA taxable income is essentially 20% of Federal taxable income. Yes, California tax rate may be higher on that income, but they'll pay the same amount of California taxes no matter where their employees are or where their buildings are.

Of course, having buildings in California could lead to higher rents or property taxes than having the HQ elsewhere. They'd have to comply with CA employment law, might need to pay a higher wage, etc. So costs could definitely still be less for an out of state HQ. But the corporate income tax would be the same.