After the release of Legendary Pokémon has been officially confirmed, we can begin to analyze interesting details that were until now unknown by the vast majority of players in the "Pokémon GO" app. Much has been said about these legendary creatures, and the players who long to have these Pokémon in their collections; however, players must know in detail each of these creatures: their movements, and where and when they appear. One of the great unknowns about these Pokémon is if they will be limited by teams when they are introduced to the game.
Next, we provide an answer to one of the burning questions that has been making the rounds prior to the arrival of the legendaries in "Pokémon GO."
Will the Legendary Birds be limited by teams?
The Legendary Birds, also known as the Winged Mirages, are the resident Legendary trio of the Kanto region. Each of them is based on a mythical bird, and each is associated with a season (though none of them is associated with autumn). As a preface, we want to address the dichotomy that exists between Pokémon and Niantic. On the one hand, they seem to do a good job maintaining links between the varying handheld games, the anime, and the movies: same pokémeon & moves, shinies, tie-ins with Eeveelutions, etc.
On the other hand, they seem determined to "use the lessons learned through Ingress" for determining gameplay and future improvements: Odd gym mechanics, teams, and Poke stops, with an ever-increasing desire for "group play " at the expense of keeping a more traditional Pokémon experience.
With that being said, we are not really sure how they'll handle the Legendary birds.
They could hew close to the game and have the player basically choose which one of the set they want (and give them a Master Ball to catch it). Of course, you could still catch all the Legendaries if you tried hard enough with ultra balls, dusk ball, and status conditions... so it's possible you'll be able to obtain all three in one account, just with a little extra difficulty.
Additional information
The idea of not giving you a chance to catch them all - or at least the opportunity to catch the one you want - seems to really fly in the face of one of the core principles of a Pokémon game - namely, to "Catch 'em All". On the other hand, Niantic can rotate the regions or introduce trading - but it's also something that seems to be a low priority with them, once again indicating that they don't care too much about allowing someone to complete the Pokedex. I'm not sure if they're afraid people will quit once they complete it.
It's a lot less complicated with Mew and Mewtwo. Of course, Mewtwo is basically one of the choices you could have made with the Master Ball too, but at least it's not somehow tied into Niantic's team mechanics.
This is all the information known so far. Keep enjoying the game, and stay tuned for more updates as they become available.