>>52070794Early 1996 shortly after the games' release, but everything else is pretty accurate. It's like how Kanto wasn't referred to by name in the west until Gen 2 whereas it was explicitly shown in the Japanese Gen 1 games.
Unless I'm mistaken, the anime, which is how most learned and knew about Pokémon during Pokémania, never showed any Pokémon shirking when defeated in battle as a defense mechanism and Pokémon were shown entering and exiting Poké Balls through lights and energy, not expanding and shrinking.
RBY had the Pokémon slide down and disappear when KOed which didn't exactly convey shrinking very well if it did.
Not even Stadium showed them shrinking, that wasn't a thing until Colosseum.