Where do I begin? Ah yes, I'll probably start with the music I wanted to hear before we had a glimpse of all of the tracks in OR/AS. When Kalos Pokemon League was first revealed as a stage, I really wanted to hear
Champion Iris's theme on that stage. Something about that track seemed to fit in with this stage really well, and it became my most wanted generation 5 track for Smash.
Ghetsis's theme from Black2/White2 and
the generation 5 Elite Four theme were a close second, as both would be another set of cool tracks to listen to in Smash. We didn't get either track sadly, though I feel like the N's Castle Medley perfectly makes up for that.
Then OR/AS comes along and we get a full glimpse of that game's soundtracks. Good lord, with arguably one of the best soundtracks in any Pokemon game, there are so many tracks in those games that would be perfect for Smash 4:
and perhaps my top two favorites:
I think the reason why we didn't get any OR/AS tracks when Smash 4 first released was because the games came out the same day as Smash 4's release, though it's because of that I thought Sakurai could've considered adding a few OR/AS tracks to the Smash 4 Pokemon stages, as that would be a good way of advertising OR/AS and acknowledging all three games shared the same release date. Unfortunately, it never happened, but when DLC stages became a thing, my hopes were revived as DLC stages would be a great way to bring in music that we wished to see implemented but previously weren't. For me, I was hoping we'd get Cave of Origin as a stage, as it perfectly represents OR/AS and it's Smash song list would entirely compromise OR/AS tracks for sure. Spear Pillar was a runner up candidate, and I thought it too could have some fitting OR/AS tracks on that stage as well.
Sadly, we didn't get a single Pokemon DLC stage. A shame too, as it meant no Pokemon DLC music. Looking back, I would've love to hear Champion Steven's theme, Brendan/May's theme, Zinnia's theme, the Gym Leader theme on the Kalos Pokemon League, while I'd love to hear the Elite Four theme, Wally's theme, Primal Groudon/Kyrogre's theme, and Maxie/Archie's theme on the Pokemon Stadium 2 stage. They would've fit those stage so well.