This is just nonsense. Once the stock vests it is yours. Now an official SEC blackout period is different. And if you are privy to insider information then yes you can be restricted but again it is the SEC that enforces this.
They can’t if you own them. Obviously the creditor can’t collect until the blackout is over but that can be written into the loan agreement. Those shares are your property. Insider trading is a sec thing, separate.
Lots of HR roles in there which is usually where recruiters are positioned. Unless you are saying all twitter recruiters on payroll are US citizens or permanent residents. Be sure to search all years.