It appears that the game, or at least the series it belonged to, was exceptionally well known and popular throughout the Koprulu Sector, newsworthy enough to make it into an info blurb on UNN. However, with the zerg invading the Terran Dominion soon after its shipping, how many people got to play it is in doubt.
The game is a reference to the game series of the same name. The Guitar Hero series is published by RedOctane in partnership with Activision-Blizzard.
2008-14-10, BlizzCon 2008: Bar Scene Part 2 (Cam) HD. Gametrailers. Accessed on 2008-11-07