Nope. They're not powdered. They use real eggs but the eggs are delivered to the kitchen in big bags that are already scrambled up so all the chefs need to do is pour onto the grill. They do contain some kind of preservative though I can't recall what. It's highly more efficient to use the pre-scrambled eggs over having to crack hundreds of eggs each morning. At restaurants where you can order eggs to-order (over easy, over hard, sunny side up, etc) obviously they would have to crack eggs open to do this.
At least is what chefs tell me. We've discussed the eggs due to allergies.