The Pokémon Sword and Shield Expansion Pass will comprise of The Isle of Armor and The Crown Tundra, which will bring over 200 Pokémon to the games. The catch? It will set you back US$29.99.
https://www.notebookcheck.net/Pokemon-Sword-and-Shield-news-Game-Freak-to-introduce-200-Pokemon-and-two-new-locations-with-paid-DLC.449840.0.html