Legendary drops can happen from opening pretty much any thing.

[Elfant 0]

I was goofing around in Dalaran, new Dal, and grabbed the quest from Blingtron and opened the present he gives you and got The Apex Predator's Claw from it. So I think anything you open that has a random item in broken shore can give a legendary.

[Lamuria 6]

its not anything the blingtron 6000 legendary chance has been around for a while