Yes, but only in Pokémon Masters and TCG.
Acerola's Mimikyu appears alongside Acerola as a sync pair.
Acerola's Mimikyu is featured in the Pokémon Trading Card Game.
Acerola (Fall 2020) was first introduced during the Fight or Fright story event. Partnered with her Mimikyu, Acerola is available in a limited-time seasonal sync pair scout.
Therefore, Acerola's Mimikyu is only appearing the side-games: Pokemon Masters and TCG, but not in any other Pokemon games.
Hope this helps!