Someone needs to speedrun up until the true end of the game, which is when you beat Senex's true form in the final Gym on Gym Island.

As of right now, we have defined anything beyond the Champion (Feng Lei) as postgame content. "Any%" doesn't imply the very end of the game, typically in Pokémon speedruns it's defined as getting to the credits, which in many cases, including this hack, involves beating the E4 and Champion.

Perhaps someone will route the post-Champion content in the future.