I would agree...if you laid out Rice, or Harris....it subtracts from the campaign. Same for Whitmer. I don’t think it’ll be announced until 18 August, and more likely that he goes to Senator Warren to improve the odds of winning.
Warren would give Biden the “woman of color” that he promised. She could also cook up the fancy crab dish that she provided from her Indian heritage for the cookbook Pow Wow Chow; all the Plains Indians spent their time in gourmet kitchens cooking up complicated crab dishes for when their husbands came in from the buffalo hunt. Its either that or Biden’s staff sees him regularly in rapid mental decline and they are frantically lining up some leftwing kook to take his place, perhaps Warren.