Quoted By:
>Note: At a later date, special rules are anticipated for Rating Battles and Live Competitions that will allow the use of Pokémon brought into Pokémon Sun or Pokémon Moon from the Nintendo 3DS Virtual Console software titles Pokémon Red, Pokémon Blue, and Pokémon Yellow: Special Pikachu Edition.
So this means RBY VC mons are treated separately from those caught in Alola and those transferred from gen 3-6
Unless they just really want to separate gen 1 movesets from the rest, I'm going to guess they have an exclusive ability or something else that's special. More genwun pandering and an incentive to buy the VC versions wouldn't surprise me one bit, either
