Tesla stock held by Elon Musk is most definitely illiquid for some rather reasonable interpretations of that word. As the CEO he can't just sell whenever he wants.
I don't understand why any of this is an issue. He can get a loan to pay now, file a 10b5-1 to sell stock in the future and repay the load then.
It's not an issue, this is a non-story.
What about when given legal fees?
He's allowed to sell, he just has to jump through some hoops. He just can't log into Robinhood and make some trades.