Niantic and the official Pokémon website have announced that from September 1st, 2019 until November 1, 2019, Flower-crowned Eevee are coming to Research Breakthroughs. Players might even have the chance to discover and catch a Shiny version of this fashionable Pokémon!

Flower-crowned Eevee are coming to Research Breakthroughs!

Trainers, We’re excited to share a few changes to Research Breakthrough rewards in the coming weeks!

Research Breakthrough Updates

• From September 1, 2019, at 1 p.m. PDT (GMT −7) to November 1, 2019, at 1 p.m. PDT (GMT −7), Eevee wearing flower crowns will be available as Research Breakthrough encounters.
• If you’re lucky, you might encounter a Shiny Eevee with a flower crown!

Eevee wearing flower crowns will be the exclusive Pokémon appearing in Research Breakthroughs during this time. Don’t miss your chance to evolve them into all the available Eevee Evolutions in Pokémon GO!

Source: https://pokemongolive.com/en/post/septemberoctoberupdate2019/

An Elegant Eevee Blossoms in Pokémon GO

Flower-crowned Eevee returns in Pokémon GO Field Research Breakthroughs in September and October.

Get ready to take on more Field Research tasks in Pokémon GO in September and October. These new tasks will start appearing on September 1 at 1:00 p.m. PDT. If you complete enough research tasks for a Research Breakthrough, you'll encounter Eevee wearing a pretty arrangement of flowers on its head. Flower-crowned Eevee was originally available for a very brief time shortly after Pokémon: Let's Go, Pikachu! and Pokémon: Let's Go, Eevee! launched. And like you could the last time it appeared, you might even have the chance to discover and catch a Shiny version of this fashionable Pokémon!

Look for Eevee with a flower crown to appear as a Research Breakthrough encounter until November 1, 2019, at 1:00 p.m. PDT.

Source: https://www.pokemon.com/us/pokemon-news/an-elegant-eevee-blossoms-in-pokemon-go/