Weren't these 10-year bonds and negative-convexity MBS? 12 months doesn't improve the position at all, but maybe you can keep applying for these loans in which case it's just another QE.

What interest rate does that assume for depositors? Sure, the face value of the bonds in 2032 dollars might have been enough to pay back the 2022 obligations to their depositors, but banks are routinely offering 2-4% interest in high interest savings accounts now. So either depositors will leave for better options, or SVB would have had to offer competitive rates (digging the insolvency hole deeper).