I see two types of VP choices:
1. A competent executive/administrator type from somewhere in the middle or middle-left.
2. A political bone throw to the identity politics crowd.
In case Joe wins, then passes away in office, we'd better hope he goes with option 1. A competent (even minimally competent) chief executive is necessary for the country to function properly.
I think he has made it clear that he's going with Option 2. By announcing that men are off the table, he's already throwing a bone to the identity politics crowd.