This may have been what you meant but wanted to clarify. If Biden wins the nomination of the party but decides to drop out before the election, he does not get to choose the party nominee. Per party rules, the DNC will decide who is the nominee. Dropping out also presents some challenges as state laws vary regarding how long before the election a party is permitted to change names on ballots.One of the British commentators on US politics mentioned a possibility of Biden winning the nominee but not actually running and nominating someone to take his place.
Short of a huge health crisis or death, the probability of Biden being on the ballot as the Dem nominee is near 100%.
