This is just the other 2024 Dem hopefuls making sure she’s not got a free ride to the nomination. Remember them all? Buttigieg, Klobuchar, Sanchez, on and on. Kamala is not going to be the Dem nominee in 2024.
An interesting thought, worthy of discussion - the viability of an incumbent who became POTUS due to death or disqualification of the elected POTUS.
Truman managed to win, only just barely. Gerald Ford and LBJ? Not even close.