I don't think that is going to happen. Biden has been busy or at least his close aides confidants have. They are not waiting for the official word and already are meeting with members close to state Governors, Congress members not just for the Democratic party either. I agree Kamala Harris is a scary being on to herself, and I have that fear that she will try to slip in some police state tactics if she can. After 4 years of Trump, I would rather have an actual caring Grandfather.
Hollander both parties have young members in their ranks, and many of the best ones in each party refuse to run for president at their stage of live, but may run in a decade or two. Who knows.