Uncle Kenny (and I say this with 100% respect for you), the point you're missing is that the song names are their literal names from the GAMES. They in no way reflect their usage in Smash Bros.
Does the song, "Yoshi's Story: ENDING" suggest that the song will only play when you beat the game with Yoshi? Of course not; it's simply named that because that was its name in the original game. Similarly, Ridley's theme in the Metroid games was called "Boss Battle Music," hence why it's called that here. One cannot infer that it means Ridley's a boss.
As Grim pointed out, if they used a Zelda theme called "Ganon BATTLE," the music in Smash would be called "Ganon BATTLE." If they used the other song, "Ganondorf's Theme," it'd be called "Ganondorf's Theme." The song's name is the same as it was in the game it came from.
All we can infer from this is that 1) there'll be a Metroid stage, 2) Ridley is on Sakurai's mind, as though four mentions in response to his poll last year wasn't proof enough, and 3) Ridley's chances of appearing have increased. Personally, I think he'll be in. Sakurai knows he's the second most-wanted character in Japan and most wanted elsewhere, and it appears he resized him and modeled him for inclusion in Melee only to hit deadlines, so now seems like the time to expand the airgame with another villain and Metroid character.
- Neiteio