It's something I've been hoping for a while now, and Nintendo have officially confirmed that Gamecube games are heading to NSO once the Switch launches.
Nintendo have announced that The Legend of Zelda: The Wind Waker, F-Zero GX, and Soul Calibur II will be launching first with other games such as Luigi's Mansion, Super Mario Strikers, Pokémon XD: Gale of Darkness, Chibi-Robo, Pokémon Colosseum, Super Mario Sunshine, and more coming at a later date.
There will also be a dedicated GameCube controller to pair with the Nintendo Switch 2 that also uses the Game Chat 'C' button for game chat functionality throughout the games.
More news to follow as it arrives!