It doesn't really matter, they're cameos in my view, since they fit the perfect defition of it:
In this case, none of the cameo Spider-Man in Spider-Society plays a major role, the major roles in this movie are played by the characters originated from it like Miguel, Spider-Punk and India Spider-Man, and the previous movie, Miles, Gwen, Peter and then Noir, the pig that I totally forgot the name and Penny.
"Played by a distinguished actor or a celebirty", Spec is in the exact same art style from his comic, so is Ben and Unlimited. They're the same characters, play a small role, are there just for "haha cool reference from my childhood cartoon" and nothing more. They enter the defition of cameo, but does it change anything? No, since they're the same from their own media, Spec is from his cartoon, so is Ben and Unlimited.
Milly thinks "cameo" somewhat makes them like, not the exact same from their original media, he got it totally wrong. They're cameo by definition.