>>42712635(2/2)
The only games which release isn't directly connected to the timeline are Ruby, Sapphire and Emerald and Diamond, Pearl and Platinum, which we know for a solid fact they were intended to happen at same time as the games remade in the same gen, the same source also makes clear X and Y weren't connected in the same way to the remakes of the time, since those remakes were already connected to other games and (time wise) it made more sense for them to be connected to Black 2 and White 2 instead.
Sword and Shield are a little trickier since there are no direct references to the timelime, but based on what we know they probably take place between 2018 and 2019 or (most likely) between 2019 and 2020, so three years after the Alola games (kinda like the Johto games took place three years after the Kanto games).
The timeline would end up like this
-Red, Green and Blue ≈ Ruby, Sapphire and Emerald | 1996-1997
-Gold, Silver and Crystal ≈ Diamond, Pearl and Platinum | 1999-2000
-Black and White | 2010-2011
-Black 2 and White 2 ≈ X and Y | 2012-2013
-Sun, Moon, Ultra Sun and Ultra Moon | 2015-2016
-Sword and Shield | 2019-2020
>inb4 but I don't think Red and Green look that old!Come on, in an anime-style game like Pokémon pretty much any adult-looking character can any age be between 20 and 40. Hell even Lusamine is older than that and she looks barely 30 at best.
>inb4 Let's GoLet's Go's character sheet for Mina says she is 14 years old and in the Alola's games Trial Captains can't be older than 19, if Johto's games take place three years after Let's Go (when Mina was 17 years old) she would reach the age limit in only another couple of years, she would be too old even before the events of the Unova's games.
Let's Go's isekai universe and the main universes are 100% mutually exclusive.