Only if the sitting President resigns or is incapacitated. If there is a new election, then it is best if she earns her candidacy.
But we all have this idea that our candidate will win in a perfect situation that the party will never give us, and while it's good to argue for choices, I'm skipping past the inevitable frustration. Harris was nowhere near my first choice, now or in 2020, but she is qualified. Realistically it's going to be her, whether we agree now or in a few weeks.
I agree that it's best if she earns it, but "earn" looks like something different to everyone and to some, nothing will be enough because their preferred candidate didn't win.