I mean, you could class it as "black struggle" in the sense that one could loosely define all black expression in America as being a reaction to oppression... but the earliest hip-hop was about partying and snorting coke. Cats were literally rapping about nothing... rapping about the shoes they wore, how many chicks they banged, what sports team they liked.

It was pretty empty textually... much like Iggy's music.

It wasn't until "The Message" that hip-hop started showing awareness of its social surroundings... and not until the late 80s that it self-consciously styled itself as an instrument for the struggle.