This is useful because, at a glance, most people would probably assume chocolate is a candy and candy is bad and the study just added another drop to that bucket of evidence.
Milk chocolate is very different. Don't take the wrong lesson from this.
The study says milk chocolate also reduces your risk by 10%.
Where do you see that? I see "No significant associations were found for milk chocolate intake" and "Intake of milk, but not dark, chocolate was positively associated with weight gain."
Ah, I stand corrected: the study starts by stating "After adjusting for personal, lifestyle, and dietary risk factors, participants consuming ≥5 servings/week of any chocolate showed a significant 10% (95% CI 2% to 17%; P trend=0.07) lower rate of T2D compared with those who never or rarely consumed chocolate", but goes on to split by chocolate types and then the positive effect disappears for milk chocolate.