Nintendo confirmed that Gamecube controller will work for other games on Nintendo Switch outside Nintendo Classics Gamecube title for Nintendo Switch Internet members. Obviously, some games will not function properly because of all buttons and features that some games require, but it's nice to know it's an option.
“Nintendo Gamecube controller is designed to use with Nintendo Gamecube – Nintendo Classics Games Collection and is an unpublished way of playing these games. Since it does not have all the buttons and features found in other controllers that can be used with a Nintendo Switch 2 system cannot be used only with Nintend.”
