Would Musk really lose $40 billion (or is it $46b), if he dumps Twitter? He could sell it to someone, Microsoft for example, at a loss e.g. $25b or $30b, which covers the loans, and write off the rest.
That said, his historical pattern is not to sell out so quickly, but rather to keep iterating until he and his team get it right.
And that was a few months ago. I'd argue that one of Twitter's most valuable assets, the blue checkmark, has been irrevocably destroyed. And if I were looking at buying it, I'd also be concerned that the technical infrastructure is a significantly impaired asset, possibly one of negative value.
That said, his historical pattern is not to sell out so quickly, but rather to keep iterating until he and his team get it right.