Here is the announcement, via The Pokemon Company:
The world of Pokemon games is more diverse than ever, with a range of titles for Nintendo 3DS, Nintendo Switch, and mobile devices. Now, Trainers can bring all their Pokemon together with Pokemon Home, a new cloud service app that enables them to continue their Pokemon adventures beyond a single game system and manage their collection of Pokemon across many of their games. Smartphone users can also trade with friends or others around the world directly from Pokemon Home. Pokemon Home connects with Pokemon Bank as well as Pokemon: Let’s Go, Pikachu! and Pokemon: Let’s Go, Eevee!, the upcoming Pokemon Sword and Pokemon Shield games, and also Pokemonm Go. Pokemon Home is expected to launch in early 2020 for iOS and Android devices as well as Nintendo Switch.