>>43753507Just before the GSC source code got leaked I was discussing how the Anime might have incorporated features from the pre-release versions of the games.
Gen 3 used to actually be the "most mysterious" generation, because its development seemed to be so opaque. Removed features, incompatibility with previous versions, etc. I mean if you look at
https://bulbapedia.bulbagarden.net/wiki/Category:Pok%C3%A9mon_that_appeared_in_the_anime_before_their_game_debut you'll see that there seems to be no pattern behind the Pokemon that appeared before release.