Following the Pokémon GO debut of Legendary Pokémon Lugia and Articuno, Niantic has confirmed that Zapdos and Moltres will soon be making their way to the immensely-popular mobile game. Here’s the developer’s official statement about Legendaries in its entirety:
These Trainers also played an integral role in revealing that Lugia would be the first Legendary Pokémon to enter the real world. In addition to Lugia, the number of Pokémon caught during Pokémon GO Fest by members of Team Instinct, Team Mystic, and Team Valor were tallied up, and, the winner was… Team Mystic! To celebrate this victory, Articuno will join Lugia in Raid Battles everywhere starting immediately. Don’t worry, Team Instinct and Team Valor, the Legendary Pokémon Zapdos and Moltres will also make their way into the real world soon, so stay tuned for more information.
Source: Official Pokémon GO blog