I think at this point they are just hoping that they can get him through his term without having to make Kamala POTUS.
IF they can do that, then they can run the governor from MI or CA.
IF Kamala becomes POTUS #47 then they are stuck with her and have to run her or they alienate their base(black women).
When Joe bows out or is forced out, Kamala will be payed off to go also. MOBama will step in “to save democracy” and they’ll pair her with someone who will bring in a battleground state.