PG-13 started on July 1, 1984 actually. Red dawn was the first to have the rating. It doesn't matter what rating Rocky is, it's Rocky ffs, it's gonna be awesome. 
I'm an internet geek so I wanted to see if Red Dawn was the first ever PG-13 rated movie. Guess what? It's not!
That distinction goes to the movie
Dreamscape, also released in 1984, with Dennis Quaid. Not a bad movie actually.
I'll keep my fingers crossed for Rocky Balboa...... I smell a stinker, though.
