MTG: How does Devour work with abilites like Dragon Tempest
No, Dragon Tempest's ability does not see the devoured Dragons when the Dragon token enters the battlefield. As you can see in the reminder text on Dragon Broodmother, the Devour ability says


  As the token enters the battlefield, you may sacrifice any number of creatures. It enters the battlefield with twice that many +1/+1 counters on it.


This means that Devour is a replacement effect (CR 614.1c), so it happens at the same time that the token enters the battlefield. By the time Dragon Tempest's ability triggers (and then resolves), the devoured dragons have already been sacrificed.