People in these states already voted. I am not sure a "do over" would even be legal. My guess is it is not.
You have to remember, that people in MI, and FL, took their primaries seriously, even if many outside their states did not. They voted. FLorida I have read has scoffed at any idea of revoting based on the fact that they feel their primary was their primary, they had it, got record turnout, and that is the result.