There has already been plenty of speculation of what else Pokemon Sword and Shield will entail. The latest rumor, or suggestion, is that the Galar region will be accompanied by the Kalos region.
Few details were released about the upcoming Pokemon Sword and Shield games. Of course we now know the titles, and already knew the game was coming in late 2019 on the Nintendo Switch.
Three new starter Pokemon were also announced: Grookey, Scorbunny and Sobble. We also got two minutes of footage (some gameplay) which highlighted the new Galar region.
Due to the sparse details that were included, rumors are circulating as to what else Pokemon Sword and Shield will feature. One leak, which was proven correct on other details, has stated a concept called armored evolution is coming.
Another rumor, which unlike the above is based on speculation, is that there will be more than one region. More specifically, it is suggested the Kalos region will also be playable. Here's the logic.
Galar and Kalos region
The Galar region, which is almost certainly based on Britain, is the setting of Pokemon's eighth region. After all, this is generation 8 of the Pokemon series.
There are a few reasons why Galar may not be the only region in Pokemon Sword and Shield, however.
Kalos and Galar at war
The first theory as to why Kalos will feature, is the story-line of where it was first playable, in Pokemon X and Y. Released in 2013, Pokemon X and Y is based in France, and within the confines of the story is at war with an unknown region.
Furthermore, there is also a train station in Couriway Town (Kalos) which is unavailable to use. During this unnamed point in history, France and Britain could have easily been at war.
Perhaps the train stations in both regions lead to one another!
Pokemon X and Y unfinished
As Qaboi states on Reddit, "Pokemon X and Y was slightly unfinished. They are the only main games in the series to never get a remake/sequel. There are few areas in the game that are inaccessible and there are some items that haven't seen any use."
Pokemon Sword and Shield's development would have started around this time, also.
According to Melmetal's Pokedex entry, it was last seen 3,000 years ago. Coincidentally, or perhaps not so much, the Kalos war also occurred 3,000 years ago.
Similar caves in Sword Shield and X Y
Elsewhere, Jaysheth1080p highlights the similarity in the caves between Pokemon Sword and Shield, and Pokemon X and Y. The obvious conclusion to draw from this is that they are, in some shape or form, connected.
Teasing the maps
In the lead up to the Pokemon Sword and Shield reveal, every Pokemon region to date was teased.
This led some Pokemon fans to believe this was a tease that all regions would be included. Admittedly, this could be some way off but even as unlikely as it is, even from a hardware perspective, this could still turn out to be true.
Nevertheless, teasing previous maps was key in the build up to Pokemon Day.
This, combined with the clues listed above, suggests it is perhaps likely there will be more than just the Galar region in Pokemon Sword and Shield.