Not all Pokémon will carry over to Pokémon Sword and Shield - Polygon

Pokémon Sword and Shield will alllow you to import Pokémon from your Pokémon Home, but only if they can be found in the Galar Region. This is for production time and gameplay balance.

Pokémon Sword & Shield guide - Polygon

Not All Pokémon Will Transfer to 'Sword' and 'Shield' on the Switch

Pokémon Sword and Shield: Isle of Armor Diglett locations and map - Polygon

Round Up: The Pokémon Sword And Shield Reviews Are In, And It's Not As Bad As You Feared

How to transfer Pokémon between Scarlet and Violet and Home - Polygon

Pokémon Sword and Shield is not reusing models from recent Pokémon games, says Gamefreak in Famitsu interview : r/NintendoSwitch

Round Up: The Reviews Are In For Pokémon Scarlet And Violet

Game Freak isn't recycling 3DS models in Pokémon Sword and Shield after all

Pokemon Sword and Shield will get a physical strategy guide. : r/NintendoSwitch

Review: Pokémon Sword and Pokémon Shield - Polygon