Pokémon GO has officially launched its new PvP battle system, marking the end of the previous battle system and the Competitors Cup. The full rollout introduces the new system as the game’s primary PvP battle experience, replacing the existing format for Trainers competing in player-versus-player battles. The update represents a major change to Pokémon GO’s competitive battling as Trainers begin using the new PvP system.
Source: Official Pokémon GO blog