According to a new leak, the Unova Stone might be coming to Pokémon Go eventually.
It’s been clear that Unova Pokémon have been introduced to Pokémon Go. After all, they are next in the series after the Sinnoh Pokémon. There have also been confirmations from Niantic, which means that we have something more solid than a (pretty obvious) guess. However, according to a new leak, the game might be introducing some of the new mechanics, as well as the introduction of the Unova Stone.
Some of the other new features could include trade evolution and new quests for World Tourism Day. It seems like trade evolution doesn’t work quite like it does in the games. Instead of having to trade a Pokémon with another player to make it evolve, receiving a trade Pokémon that has the trade evolution feature from a friend will remove the candy requirement to evolve the Pokémon. Otherwise, the Pokémon can evolve as normal with the right number of candies. The new quests mostly involve friends, making new ones, sending gifts, and trading Pokémon across a certain distance.
The Unova Stone is probably the most interesting upcoming feature in the leak. It is a type of stone that can make certain Pokémon in the Unova region evolve. It will most likely act similarly to the Sinnoh Stone, which already exists in the game.
However, there is an important difference between Sinnoh and Unova Pokémon. Many Pokémon that first appeared in the Sinnoh region evolved from Pokémon from earlier generations, such as Gliscor, Honchkrow, or Porygon Z, which evolved from Gligar, Murkrow, and Porygon 2, respectively. So, when Pokémon Go added Sinnoh Pokémon to the game, new cross-generation evolutions occurred via the new Sinnoh Stone. However, these sorts of evolutions don’t occur in Unova. The new Pokémon found in Unova are separate from the evolutions of the previous games. It’s unclear how Pokémon Go would implement Unova Stones since they are pretty different from Sinnoh Stones.
Unova Stones might only be added to the game since it's the next step after introducing Sinnoh Stones. Since Sinnoh Stones can be tough to get outside of battles, it can be frustrating for players to get enough of them, and it looks like Unova Stones might be the same. However, this is only a leak so far, so take it with a grain of salt.