According to Nintendo, the recent update that enabled the GameCube controller to be supported on Switch was an accident rather than intentional.
The latest 4.0.0 update gave the Wii U GameCube adapter a full controller support for the Switch, however, Nintendo of America’s president, Reggie Fils-Aime explained in an interview with Kotaku that:
“In our latest system software update, it enables third-party peripherals to work on Nintendo Switch. As a result, the peripheral for Wii U that allows it to attach GameCube controllers also works [...] I think it’s fair to say [...] that that peripheral working was as much a surprise to us as it was to consumers.”
This “accident” as Nintendo claimed, led some people to believe that a GameCube virtual console is finally coming for the Switch, and when Fils-Aime was asked, he simply said that:
“Of course, there’s nothing to announce on this, I think it’s fair to say, Stephen, that that peripheral working was as much a surprise to us as it was to consumers.”
This is a bummer for those who thought that Nintendo is giving a clue that a GameCube Virtual Console is in the works, and although nothing is set in stone, let’s not keep our expectations high for now until they make an official announcement.