Bezos may not be able to sell his shares in significant amounts, but he can sure use them for collateral. This is a very basic strategy for the super rich...
Bezos uses it to spend his pile of money, but for one Bezos there are 100 businesses who use the same exact instrument as a perfectly legitimate way to borrow money.
It’ll be extremely hard to draw the line between both use cases in a way Bezos couldn’t exploit it.