I found this thing on Wikipedia as an image, but it doesn't say which pages was this used at. I kinda doubt that it's an internal logo used by Nintendo (mostly due to the registered and unregistered trademark symbols both being present), but the font looks like something that Nintendo uses. Not to mention the gradient going from red to blue - the default joycon colors.
Was this a fan mockup of a potential HorizonOS logo? Is there another HorizonOS that uses this logo?