Same has been true for bill gates for a long time, so it's a fair game. I mean figuring out what's liquidatable or not for each individual is not really a feasible task anyway.

The way it's normally done for those kinds of people is they take out a big loan secured by the stock, which is sold over time.

So while it's technically true he can't liquidate all his shares, he can cash out if that's what he really wants to do.