Players have discovered new coding that suggests that the legendary Pokemon are not just in the game already but Niantic is planning to release them very soon. While this is not official information, it would make sense for Niantic to look at releasing some legendaries soon considering that Generation 2 is due for release next year.
The games code now includes “Activity_catch_legend_pokemon” which is completely seprate to the current active code which allows players to catch wild Pokemon. This addition to the games code is quite cryptic, it’s very limited and Niantic is yet to comment on the issue of legendary Pokemon in the game.
Other details discovered by players is about the Buddy System which also suggests that legendary Pokemon are coming very soon; players will be able to equip legendaries as their Buddy and will need to walk 3KM with them to collect Candy.
The Master Ball gives a 100% catch chance to trainers and is not in the game yet, it’s thought that they will be added to the game with the legendary Pokemon; data miners haven’t found anything about this type of Pokeball in the coding just yet so it’s uncertain if this true.