Yes, it is theft.
If you dont want to provide a loan, fine. I dont see how you justify seizing the company.
Imagine asking the bank for a loan and they say "no, and we are also taking your car".
The constitution requires paying fair market value whenever a company is nationalized. Theft would be unconstitutional.
The correct analogy is the bank securing the loan with the car, and then potentially repossessing that car.
Don't ask for a loan if you don't want a loan.
We're explicitly talking about a situation where BigTech and AI labs ask the government for money or (very hypothetically) allow coordinated defaults to spill out into the banking fabric
In those cases, the economy and society you want to externalises losses onto has every right to negotiate something in return. We are not in the business of just forgiving multi billion debts.