Hot take, but I feel that if the next Smash makes major cuts, Pikachu should be at least considered for the chopping block - he comes off to me more as a rep for the Pokémon marketing machine than Pokémon itself, Pokémon Trainer and his team (or even just Squirtle or Charizard alone) fit the "mandatory main protag" bill better, Pokémon has grown to the point where just Charizard or Mewtwo could get box art sales, and I can't imagine many people saying Pikachu is their favourite Pokémon.