Niantic has announced this morning that Pokémon originally discovered in the Sinnoh region, featured in Pokémon Diamond, Pokémon Pearl, and Pokémon Platinum, will soon begin to arrive to Pokémon GO.
Trainers should start keeping an eye out for Pokémon including Turtwig, Chimchar, and Piplup and can look forward to more Pokémon originally discovered in the Sinnoh region making their way to Pokémon GO in waves in the future.
You can find the blog post on the announcement here https://pokemongolive.com/en/post/ and directly below for easy reference.
