An article by Children's Hospital Colorado lists some of the health benefits of low-fat chocolate milk, such as a protein source for muscle repair, replenishing necessary vitamins, and providing electrolytes for hydration.
The article is a bit short, however. Even though it lists 10 health benefits of chocolate milk, it doesn't go into depth on each of the reasons explaining why it's a health benefit, limiting a lot of information that the article could've provided, allowing for clarification to the audience reading it.