I agree, SC. Times had changed ("Tempi cambi"), as Michael said to his mother.
Many of the problems that Michael faced, were unknown to Vito. Not only the disloyalty of his brother but also the concept of women's liberation. Vito's wife would never have left him.
But on the other hand Michael never really tried to build friendships. He never even trusted Tom. I think Vito would never have gone to Cuba and let his family (I mean his real family) alone.