Pokemon GO officially unveiled its Spring Equinox event yesterday, which is slated to begin on March 19 and run through March 26. The developer Niantic has confirmed increased Grass-type spawns, new Field Research, new Raid Bosses, and more. Like other Pokemon GO events, there will likely be smaller bonuses accompanying this, but one growing rumor is that Niantic will use this event to finally add Glaceon and Leafeon as one of the bonuses. Before moving forward, it's worth highlighting that this is entirely speculation and has not been confirmed by Niantic.
It should also be brought up that this isn't the first time the masses hoped Niantic would add Glaceon and Leafeon. During the Eevee Community Day, many thought their time had come because of the two-day nature of the event. This didn't come to fruition, of course, as neither has yet to appear in Pokemon GO.
There are arguments to be made both ways that suggest Niantic could add or not add these Pokemon. First off, the nature of the Pokemon GO Equinox event itself would lead some to believe it's a good time for their addition. It is warming up in the northern hemisphere and cooling off in the southern, which corresponds with the Grass-type Leafeon and the Ice-type Glaceon. Of course, this could also mean that they are added as regional exclusives until the next equinox, but that's neither here nor there.
There are also various viable methods to have these Pokemon appear in the event. There is confirmed bonus Field Research that could potentially reward Pokemon GO players with something leading to either of these Pokemon or they could even be added as Raid Bosses as part of this event. More than that, Niantic has shown its player that its willing to use events to introduce Gen 4 cross-evolutions, such as when Mamoswine was featured in the Swinub Community Day.
All of that said, there are plenty of reasons Niantic may not add these fan-favorite Pokemon. It may simply not be ready, there could be some issues to be resolved concerning the Sinnoh Stone and the random evolutions of Eevee, or there could be some other plan down the road for their addition to Pokemon GO. The smallest detail players are unaware of could be reason enough to not add the Pokemon.
Regardless, many are hoping we finally get to see Glaceon and Leafeon appear in the game because the various eeveelutions are incredibly popular in the world of Pokemon, and adding these two to Pokemon GO would only leave Sylveon to be added at a later date. Until the event begins, however, we must simply wait and see.
Pokemon GO is out now in select regions for Android and iOS devices.