According to MD, Messi won't authorize this movie. His legal reps published this note:
"In relation to the story that appeared today on the interest of a producer on a film based on the book by Luca Caioli, the Messi family wants to express their great surprise and disagreement. First, because it is an unofficial biography and some excerpts from the book are not accurate. Moreover, no production company has contacted the family to ask permission. Finally, we take this note to show that the Messi family has no interest in making a film on the life of Leo Messi. "