Also so far he has displayed very little understanding of what engineers actually do (the bring you screenshots thing and the way he responded to one of them correcting him on Twitter and a bunch of other cases don't paint the brightest picture).
I don't think he can run Twitter very effectively out of San Francisco going forward, after his behavior. He'll try to run it out of Texas instead.
I assume he already laid off most h1bs, who would say and do anything to not get deported but might not be the best engineers.
Still, the people that claim to work 'hardcore' might just say that. They might survive for 3 months, which is how much severance they are forfeiting.
He will move the Twitter HQ, within 12-24 months I'd guess. He'll move it to Texas. Most likely he has already begun preparations for that and we'll see an announcement within six months.
He's trying to decimate the workforce on purpose, although it's not going as smoothly as he hoped from outside appearances. He wants huge numbers of Twitter employees to quit, and he has been very clearly laying out the terms for behavior for the type of people he would like to run Twitter with. He's intentionally shaking the tree violently. He's hoping that the types that remain will be his types of employees. He's going to try to rebuild the workforce starting from those, so it's his company in ethos / function.
He thinks Twitter can run with far fewer engineers, and drastically fewer staff overall, than what it was operating with previously. He knows the value of engineers, he has made that part clear: he plainly said that engineers are most of what is important about Twitter, not the rest of the staff, he said it should be an engineer heavy company.