Twitter user CentroLeaks has been on a posting spree over the past few days, relaying collected information from a pair of leakers that have supposedly played/seen early versions of the upcoming Pokémon Scarlet & Violet. The barrage of info has been constant, but the details have either been quite vague, or too small to warrant much discussion. As the days have gone on, however, more information has gotten revealed, and a clearer picture has been painted. If the leakers are correct, this generation may bring a new type of regional variants, in the form of ancient and future Pokemon.
CentroLeaks has reported accurate leaks in the past, such as with Pokémon Sword & Shield and Pokémon Legends: Arceus. CentroLeaks references two leakers, and though each seems to be providing their own unique details, some of the same information was coming from both.
The two new professors matching the ancient/future vibe.
This is what is being claimed right now: The games will have a form of Pokémon species variation yet to be seen called ancient and future forms. These have a significant difference from the regional variants the Pokémon player base has become accustomed to since the seventh generation of games; they will have their own names and their own Pokédex number. Though they are technically ancestors or descendants of certain Pokemon, they are classified as their own Pokémon, as they are not region-dependent, but rather prior or future states of their species. It was claimed that these species do not evolve and have high stats.
That's not all though. There's another different type of variation that CentroLeaks is calling convergent species. These are supposedly Pokémon variations that have nothing to do with a previous species, however, simply look very similar to them. It's said that these Pokémon are based on the "Convergent Evolution" concept from biology, in which unrelated animal species adopted similar traits to others by happenstance as they evolved (think wings on bats and birds). These Pokémon will also have their own name and Pokédex number.
Furthermore, there are allegedly actually still regional forms, meaning the style that we know, will function as we've seen; these will have the same name and number as the original Pokémon, but a differently-typed variant. There are also some new evolution lines for Pokémon. These aren't any type of variant, just evolutions for Pokémon that previously didn't have one, or new evolutionary lines. CentroLeaks went on to post a chart of the Pokémon that they were told would be getting these various forms. These are not all; if the leaks are true, there could be more.
The red text Pokemon are ones "unconfirmed," as stated by CentroLeaks.
As seen above, though deemed unconfirmed, it was stated by one of the leakers that two pseudo-legendary Pokemon would be getting an ancient/future species, theorized to be Salamence and Tyranitar, due to the trade seen in the most recent trailer, suggesting that each would be version exclusive. CentroLeaks has aptly titled this the "generation of clones."
To provide more context for information that was previously reported, the supposed crystallization gimmick of the game seems to provide Pokemon with a new STAB boost. Basically, a Pokemon can hit harder with a specific type of move (Fire, Water, Bug, etc.), without having that type's weaknesses. Another more recent interesting detail is that Pokemon breeding might no longer require handing two Pokemon off to daycare. Eggs, however, are still in the game.
There is a lot more information floating around online, but as always, everything should be taken with a grain of salt before it has been officially confirmed.