Are the iPhone 7 EarPods longer?
You've answered your own question - if you see that they are longer, then they are obviously shipped with longer headphones - but for everyone else, I compared them.

The distance from the cord split to the ends of the headphones is the same; however, the distance from the edge of the connector to the split is approximately two inches longer on the iPhone 7 (Lightning connector) EarPods than on the iPhone 6s EarPods.