New generation of Pokémon coming to Pokémon GO
What's more, as many as 100 new Pokémon and 52 new Pokemon families are being referenced inside the game's code, although an update will be required for them to start showing up. New code for anti-gym sniping has appeared, issuing an error message if you are locked out of a gym. Finally, daily quest code for daily and weekly bonuses has appeared.
According to the source, it might take weeks or months before Niantic makes the necessary client and server-side changes to make the new generation of Pokémon appear. But the presence of so much new material suggests that Niantic is staying busy keeping the AR game up-to-date and players still have a lot to look forward to.
source: The Silph Road