Imagine way more Pokemon songs, and Pikachus instead of Lantern Eels here, perhaps.
If you have a Wii U, in addition to playing the three Wii U Taiko no Tatsujin games on it, probably you also have Pokken Tournament, the Pokemon game that have Pokemon actually fighting instead of just menu controls.
Tekken series producer Katsuhiro Harada (原田勝弘) told The Verge in an interview that what would have become Pokken Tournament was initially going to be a Pokemon-themed Taiko no Tatsujin game (imagine im@s Must Songs). However President and CEO of The Pokemon Company Tsunekazu Ishihara (石原恒和) spoke out in a BNEI corporate meeting that he would rather see a Tekken collaboration instead, hence birthed the idea.
That probably wouldn't stop Pokemon content to continue appearing regularly in Taiko. Having "just caught up" with the newest games in the Pokemon (game) medley front with ORAS Medley, there is some chance that something will come up when Pokemon Sun and Moon is out... somehow.
Source:
Webster, Andrew (2016-02-17). How the minds behind Tekken and Soulcalibur transformed Pokemon into a fighting game. The Verge. Retrieved 2016-04-17.
