No, they directly insure $250k and repeatedly and consistently demonstrate their ability to recover everything else by repossessing failing banks and selling them to other parties. They don't promise it's all immediately available past $250k, so it may take some time, but for you to expect a haircut you would need an example of someone getting one.
I would prefer this be more explicit policy though.
> That's an irrational thing to do when your money is at risk.
If you know what a bank run is you know this is causing it, so this is bad game theory (as we see since it caused the bank to fail). You should actually pursue a strategy of stopping everyone else from withdrawing. Screaming at all your founders and panicking in group chats is not that.
> Also strange to claim that they don't have a bank anymore...
They ain't got one. SVB no longer exists. If you want a new checking account for a new business you cannot get one from DINB of Santa Clara.
The FDIC insures up to $250k only. You are not asking for confidence but for faith that somehow they'd be willing to guarantee 100% out of their good hearts. That's an irrational thing to do when your money is at risk.
Regarding your second paragraph: hindsight is such a wonderful thing! Also strange to claim that they don't have a bank anymore...