It's been rumored (and fairly obvious) for a long while now that the third generation would be making its way to Pokémon GO. However, now it seems those rumors have come to an end with an official announcement from The Pokémon Company this morning:
“Get ready to do a lot more exploring when Pokémon GO introduces a huge update that will expand your Pokédex and change the way you play! Dozens of new Pokémon originally discovered in the Hoenn region will soon start appearing for the first time. You'll be able to catch Treecko, Torchic, Mudkip, and many others, with even more Pokémon waiting to be discovered in the next several weeks.”
via destructoid http://ift.tt/2B7kr9e