Every election you have celebrities and wealthy individuals threaten to leave the country, etc. Nearly none of them follow-through, and of the ones that do, many ultimately move back.
Page left California specifically because of the so-called "Billionaire Tax", and is taking with him his family (which will inherit his vast riches), his philanthropy, his non-profits, many jobs, taxes and more. The effect will be generations of lost benefits to California.
Yeah; there's absolutely no way he could possibly support philanthropic efforts in one state from another. Nope; everyone now loses out because of it!
There is absolutely 0 reason that someone worth $270 billion needs to worry about the 5% tax. The 5% tax will reduce his estimated worth by $13.5B bringing him to a paltry $256.5B.
To put $256.5B in perspective: over two /lifetimes/, he would need to spend around $4.5MM a day to exhaust that number, assuming it did not grow exponentially over that same time.