Treecko, Torchic, Mudkip, and more Gen 3 Pokemon are coming to Pokemon Go soon, as evidenced by the latest datamine from Pokemon Go fan site The Silph Road. Digging through the files of APK version 0.71.0, these poke-sleuths have discovered data for all 173 Gen 3 critters, from Treecko to Deoxys.
Don't get too excited just yet, though. Developer Niantic often updates major additions in stages, and that seems to be the case here as well. Though each of the species was discovered in the new data, there are currently no sound files associated with them, nor were any additional moves added. So it'll be some time yet before Gen 3 'mon start appearing in your backyard.
For comparison, Gen 2 Pokemon data was first uncovered by The Silph Road in November 2016, while the actual Pokemon didn't appear in-game until February 2017. So it could be a few months before Gen 3 shows up - or, if you're an optimist, maybe you choose to believe that Niantic has gotten better at this since then, and we'll see them sooner rather than later.
There also appears to be new data related to the Exclusive Raids feature, which will let trainers earn new items and emblems. Raid timers and spawn timers have also been tweaked - The Silph Road notes that this doesn’t necessarily mean traditional Raids will change, but also suggests fans keep an eye out and see if they notice any improvements.
For those of you who rely on egg hatching to expand your Pokedex, a new item referred to as a "Super Incubator" seems to be on the way as well. As you can imagine, the Super Incubator is believed to hatch eggs faster than a typical one, though it's not known if it will be an item players can purchase or if it will only be given as a reward for spinning Poke Stops and winning Raids.
Oh, and of course various bug fixes. Wouldn't be a Pokemon Go update without that.