In most cases I would say you are correct, but this would be an extremely rare exception. OpenAI has about 7000 employees, and has raised a round at a $500B valuation with a realistic shot at a $1T valuation at IPO. That's a range of $70-140M of equity value per employee. So if employees hold 10% (and that's a low estimate) it's an average of $7-14M per employee. So for the average employee leaving CA before IPO would be a $1 million benefit over paying CA cap gains taxes.

Of course that isn't distributed remotely evenly and a lot of employees have not nearly enough to want to leave CA over taxes or just don't want to leave CA for other reasons. But OpenAI could easily say "HQ is moving to Austin. All employees must relocate and will be given $1M relocation bonuses." And the part left unsaid would be "Failure to comply means you lose 7 figures of options." Take rate on that would be >95%.