Like you catch a Magikarp in ZA you can't put it Let's Go, Sword/Shield,Arcerus or Scarlet/Violet it can only be used in ZA and the future Champions game.I don't know why people care about this. You can start playing Pokemon Scarlet and within the first 30 minutes of the game you can catch pretty much any Pokemon you want, you just need to run to wherever its location is.