Some foods are listed as "all life stages" and are appropriate for puppies and adults. Maybe that is what they meant. Plus, not all puppies need puppy food and some older dogs need puppy food - so it's always good to check with your vet and/or trainer if you have one. I take my trainer's advice on nutrition over my vet's since the vet recommends Eukanuba...
Calling the company is a great idea - Solid gold is a great food.