Why call it 1950s style when it was most common mode of operation up to 2019? Elon already insisted Tesla engineers work on-site, so this move isn't too surprising. What leaves me puzzled is why would anyone decide to work there. Where's the carrot?
I guess the pay is the carrot. As long as they pay well for the requirements, there will be plenty people to take it. And if the job market deteriorates, they might not even need to pay that well...
Also the mission. If I didn't have a great gig right now, I would absolutely join Twitter, just for the opportunity to add new features and prove that the old Twitter was sorely underperforming and that Twitter can be a force for free speech, which I believe in an absolute right.
Elon's companies aren't known to pay particularly well. I got an offer at one of his companies that was such an insane lowball it was hard to take seriously.