I think he'll make it.
Not only does it look like Twitter will survive (if the mass-migration to another platform hasn't happened yet, when will it? If the site runs stable after the initial shock, why would it run less stable later?), it just might make Musk more powerful than we could ever imagine. Contrasting with other social media founders/owners he isn't shy to use the platform as a very personal thing, to actively shape the discussion and to pick and fight fights. The potential power he could potentially wield makes the purchase, as well as possibly running Twitter as a loss, worth it.