These threads (and the comic book equivalent "could Superman beat Goku?", etc.) never make much sense because there's never any context to the question.
Does Michael Corleone need Walter White in any way? Is it a Gus type situation? How would the two meet? What is the nature of the beef?
If it's just "Michael Corleone wakes up one morning and decides to kill Walter White"....then yes obviously Walt is dead. If there's any reason for Walt to be able to weasel his way into that operation, or he's needed as a chemist....or hell, I don't know because I don't know the context....basically if there's any leverage Walt could have, to extend his life long enough to plot on Michael Corleone, then the answer isn't as clear.
Fred.