All that doesn't mean squat as the states call the shots.
And every state has a cut off date for changing candidates.
This is why California changed their ballots to have POTUS and VPOTUS share the same checkbox. Before that, you voted separately for the two.
This way if Biden dies past the deadline, all the votes go to a slate of Electors who will vote for Kamala event hough she isn't registered as running for POTUS.
https://democrats.org/wp-content/uploads/2022/03/DNC-Charter-Bylaws-03.12.2022.pdf