Pokémon Pokopia doesn't share much in common with the wider Pokémon universe, as it's set at a time when all of humanity has disappeared and Pokémon are left to fend for themselves. However, it has plenty of references, along with lore-themed collectibles such as newspapers and electronic devices revealing information about when humans and Pokémon co-existed.

Through these collectibles in the Bubbly Basin DLC, it has now been confirmed that Pokopia is set in the same universe as Let's Go Pikachu & Eevee (henceforward, LGPE). Trace, a trainer exclusive to that game (and the player's best friend/rival), is named in Pokopia as the champion of Kanto. Not only that, but May, the female protagonist of the Emerald, Ruby, and Sapphire series and their remakes, is named as the champion of Hoenn, which has never been revealed before.

This was initially discovered by X user rasenburst, who shared screenshots of the collectible's text:

"The story of Trace, former Champion of the Pokémon Kanto League, and his faithful companion Marowak is now available as a picture book!" reads the entry. "His fateful encounter at Pokémon Tower, the adventures that led him to become champion — it's all available as a charming tale that is perfect to read along with your children!"

The idea that Pokopia shares a universe with LGPE has been circulating ever since the game launched, because the two have a lot in common, and we're not just talking about them both being Pokémon games. Vermilion City, for example, shares numerous objects and textures with Pokopia, including the road surface and streetlights, while LGPE concept art could easily be from Pokopia.

It's a thin lead, but no doubt this will spark rumors of an LGPE sequel set in Hoenn. In theory, Johto should come first since we've only seen the Kanto region so far, but there often seems to be no pattern in which regions The Pokémon Company decides to visit, so we could well see Hoenn up next. After all, LGPE has plenty of avid fans, despite it being a much more child-friendly, stripped-back version of the Pokémon games.