As far as i know, costume brawl skills do not affect people outside of costume brawl. Even when you check the skill description, the fear clearly states COSTUME BRAWL fear. So i highly doubt that was the reason for its removal and if it was, then they might as well take away all the tonics cuz omg costume brawl so terrible right? Also if the “dash” skill was the problem, why not just remove that skill? Disabling the entire tonic is just taking it to the extreme…..