If it isn’t Kamala, they lose access to their campaign funds. It has to be her.
But it won’t happen. As the great LS points out, there are three swing states that the republicans could plausibly keep her off the ballot, unless he is declared mentally unfit. I don’t see the Biden family allowing that legacy.
Cold equations—the current campaign fund bank balance is less than 10% of that needed until November.
It is a non-issue.