Did you read the article? They are making the case that communities are using early marriage as a way of covering up rape in places where underage sex is legal

Did you read the article? They are making the case that communities are using early marriage as a way of covering up rape in places where underage sex is legal (or at least overlooked) if the person is married. Hence banning it would reduce the amount of rape going unpunished, and therefore the amount of rape.