Rock, Rock Encore, and Heavey Metal Meltdown are among some other early pinball rock themes that incorporate the guitar riff well.
Those, along with Eugene Jarvis in the 80's and then Getaway in the early 90's, (and to a lesser extent Judge Dredd) guitar riffs eventually evolved into incorporating fully licensed bands into games. It's no accident that Getaway and games like BTTF had "singles" licensed to the creators of those games. It eventually evolved into an entire game, themed around the actual band's songs.
I consider Tommy to be the first actually liscensed rock music themed game where the songs actually BECOME the game. It came out just months before GnR.
Sure you have early games like Bally Kiss, Rolling Stones and even Nugent but the songs are not "the game" for a reason. They really have nothing to do with the gameplay. It was just not feasible at that time to attempt to incorporate the actual music into the gameplay in the late 70's. Beyond the Kiss tune when you start the game, I can't really think of another licensed song in a pinball machine until BTTF, which came out in 1990.