During the early stages of development, Galar was planned to have 102 new pokemon/galarian forms, about 20 of which were completely scrapped from the final product, the developers were super stressed and rushed the game, half the post game content didn't make it to the final version.
> Solosis was going to have a Dark type Galarian form that evolved into some sort of cancerous tissue, but the concept was ultimately removed for not being child-friendly;
> The Inteleon we know was a rushed concept and not what its designer was originally going for. Inteleon was going to be Water/Ghost with a long tuxedo and a fedora made out of its frills. It was also supposed to have an umbrella for a tail. The fingerpistol concept was kept, however;
> Greedunt line was a joke concept the designers came up with. The original early rodent was going to be a Normal/Rock praire dog, but the concept was later thrown away;
> Galarian Persian was planned to be a Steel/Ghost melting lynx, but got removed with Purserker's creation.

Game developers are already working on a BW2-like sequel codenamed pokemon Arrows. It is planned to have a bigger post game and Hop's children as the main characters in a world where Eternatus wasn't defeated, with the main villain being Sword and Shield's male protagonist.
There has been no talk about including national dex back, just expanding the already existing one with discarded concepts for gigantamax pokemon like Arcanine and Golurk and about 100 extra pokemon.
Galarian formes are being discussed, with concepts for the likes of Slowpoke.
> Galarian Psyduck is less dopey and more intriguing. It evolves into a pokemon other than Golduck with a huge pulsating brain;
> Early Galarian Cacturne design reveals it has a huge machine gun and has a cloth covering its body. Very far westish. Also, Ground/Steel which is dope.

Also, you'll know my leak is real when James is gets a Polteageist on the anime. Bye for now.