Call me lucky then. Because I have Hellcats and Lightnings in my AA50 set. It has never been mixed or had anything added or taken away. If you look on the back of the box of Spring '42 first edition you will see a US Hellcat in Africa also, even though it was in that edition.
Hmm…very puzzling. I don’t recall my copy of Anniversary containing Wildcats, so either I’m mistaken or I got a variant printing of it.