The bigger risk if your poor is not having access to your money while the FDIC sorts out the problems. Now, I don't know how long it would take to restore access to your money in a bank closure but, for a lot of these people, having your funds frozen for a week or two would be crippling.
There was a This American Life episode during the financial crisis when interest in bank failures was high. They followed an federal takeover of a bank, and from what I recall, it was an extremely swift and surgical procedure. The don't inform the bank ahead of time when they're going to take it over, because the last thing they want is a bank run. For that reason they also try to disrupt banking hours as little as possible if at all.
There are also instances though where the FDIC can't find another bank willing to acquire the failed institution, so it can't just close on a Friday and then reopen on Monday as a branch of a new bank.
So it seems like in an instance like this, while you get a check for your insured deposits from the FDIC, your bank is gone and presumably any auto-debits or outstanding checks would fail to clear. You get to wait for the FDIC to mail you a check. Then you'd have to find yourself a new bank. This seems like something that would be fairly disruptive even if you are not poor.
