This isn't correct. SAFE isn't a debt instrument - its a right to own shares in a future round. You are probably thinking of convertible debt.
If you wind the company down, you would/should try to make your investors 'as whole as possible'.
Debt implies that at some later date YC could come asking for their $375k back. A SAFE is not debt.
If your company is running and does not end up raising more money that SAFE should just sit there waiting for the day that you do (which may never come).