That's not an option. They all have to sell their shares. It was a corporate decision.
In fact their was another vote that meant Musk couldn't accumulate more than 15% on the open market.
It's 100% not. It's secured debt, that's it. If Twitter becomes worth $17 billion, they get - $15 billion. If Twitter becomes worth $170 billion, they get - $15 billion.
To say nothing of if Musk misses a payment, are they really going to foreclose? Or would they renegotiate?
I’m not sure exactly how the coinvestors fit in the picture, but I expect they (or more likely their own holding companies) own minority stakes in the parent holding company. The debt is probably the parent company’s also, although Musk may have personally guaranteed much of it.
Also, probably even the parent holding company is not directly owned by Musk. Probably owned by one or more trusts he controls.
He got rid of the last CEO and will presumably either take the position himself or put his own guy in the chair