Then the company can hire more engineers? Even if devs in SF virtue-signal on Twitter about how they'd never work under Musk, a competitive paycheck attracts outsiders.
Any engineers capable enough to rescue this trainwreck will likely be able to secure better compensation elsewhere without having to endure Musk's new indefinite "hardcore" death march.
Twitter is going to operate on a skeleton staff of H1B's dependent on their employment for their visas (who are probably already floating their resumes) and whatever underqualified graduates they can hire.
Institutional knowledge is necessary to sufficiently onboard any new hire, without that you have headless chickens running around trying to figure out what exactly are they working with. How do you solve Chesterton's Fence when there's no one around to tell you why the Fence is there?