A lot of events in League give us a short track that plays at the beginning of the game before transitioning into the main music, and once the event is over, that music is also gone for good. It would be cool if some of that music could be preserved because it hypes you up as the game starts. Since the music playing right now is based on GIANTS, it would be cool if it was kept as a permanent feature of the True Damage skins after the event.
Star Guardians and Gun Goddess Miss Fortune also have music that plays at the beginning of the match, so it makes sense to include it for the MUSIC SKINS as well, especially since it's already in the game.
While we're at it, the beginning of POP/STARS played at the beginning of each game this time last year last year, and it would be cool if that would be added to the K/DA skins as a permanent feature, as well.