While the Eevee community day event is over, there have been a few threads over Eevee’s special day(s). Not only was Eevee an odd choice for Niantic’s next community day, but also, it was the first Pokemon to get two days instead of the normal one.
Several people were even mentioning a larger amount of shiny encounter, which, a lot of this is probably due to the fact there are more than one evolution Eevee has. It’s not like any other Pokemon when evolving either. For Jolteon, Flareon, and Vaporeon, you have a chance of Eevee evolving into one of the 3. However, Eevee also has two more evolutions out along with three more to come.
This explains the higher shiny encounter rate, but not really the two days of fun; this shows Niantic may increase the days on other Pokemon as well to allow players to collect all their shiny Pokemon hopefully. Here is what we know about the community day events before Eevee.
After Pikachu CD, Community Days alternate between starters and a random rare Pokemon. Some think Pikachu, by not matching the trend it suggests this trend is wrong. But others simply explain it as a “universal game mascot” exception to the rule
Said rare Pokemon is presumably a 3-stager from the 10km hatch list and is highly valued in the meta (or could be made to be so via the CD-exclusive move)
Has a shiny form not yet released in PoGo
The likelihood of an Eevee Community Day was heavily debated.
Those arguing that an Eevee CD wouldn’t happen claimed that Eevee isn’t a starter nor a three-stage Pokemon, and would break the prevailing trend, thus deeming it unlikely to happen.
Those arguing that an Eevee CD would happen claimed that Eevee is technically a starter – it was Pikachu’s counterpart in Yellow and the anime and is a legitimately playable starter in some spin-off games.
An Eevee CD was also argued to be in good timing for promoting the upcoming Let’s Go Eevee release, as well as a rumored new Eeveelution for the upcoming Gen VIII
Eevee CD was predicted for Sep, as the next starter CD month, or Nov, coinciding with Let’s Go Eevee’s release
In any case, there’s no consensus on what the CD-exclusive move would be. Either possibility mooted – all Eeveelutions get their unique move vs. only the base form gets it – made sense, so it became another reason to believe an Eevee CD won’t happen.