I actually think it's probably pretty simple underneath the facade - Musk offered to buy Twitter for a lot of money. The market tanked and Musk doesn't want to pay that price any more. He thinks he can strong-arm Twitter and either not go through with the purchase or force them to accept a lower price. The law does not support this, but Musk has a history of being unbothered by the law and there are examples (not Musk) where this tactic has worked to reduce the purchase price by hundreds of millions of dollars.

Everything else is just window dressing.