I'm not buying Kirbyoshi's claim. For one, I think the way he introduced his song was awkward. The way he says "I don't think scum can have a song, right?" stands out to me as "this is a detail I should only know as town, right?" when nothing has been confirmed.
Going off of what Overswarm said, concerning that only the "Top Hits" of her collection would be present as members, the song "He Wasn't" wasn't released in the United States AS a single and was the FOURTH single off of her album in the United Kingdom. I know we aren't dealing with an exclusively American population here, but it would be reasonable to assume that the songs picked to represent each candidate were most likely Avril's best-known songs.
Likewise, I find Kirbyoshi's attack on frozenflame to be a mini OMGUS, basically without the voting part. It's sort of like "You find me scummy? Yeah, you too buddy" and that doesn't really sit well with me.