DeSantis needs to remain in Florida or Florida will be lost. Then it won’t matter what Republican runs for President. They won’t win without Florida.
Then it is Trump. DeSantis did say that he intended to serve the people of Florida; at the time he said this it seemed very much he wanted to serve two terms as Governor.
It would be extremely odd that DeSantis and Trump would not in some way coordinate their strategies. My money is that if one of them runs for president the other will not enter the primary races. There would be no point in having a bloody battle when it is imperative the Democrats must be defeated in 2024.