It seems like Nintendo may have inadvertently leaked that a Nintendo Switch version of Metroid: Samus Returns could be currently in the works; if true, this could also mean that the game could end up being released rather sooner than later, and we'll explain why.
This information was first spotted by YouTube user PapaGenos, who noticed that official Super Metroid decals for the Nintendo Switch popped up on Nintendo's official website, and one of the images on the site shows a person playing on a Nintendo Switch that has these decals already applied on the Joy-Con controllers.
The game that this person is playing, however, is Metroid: Samus Returns, which is a remake of the GameBoy's Metroid II: Return of Samus that released for the Nintendo 3DS in September of 2017; a game that many considered should've been released for the Nintendo Switch instead of the 3DS.
Now, this is could well-be done in photoshop, but that particular image of Metroid: Samus Returns does appear in the opening sequence of the game, that's why it is important to take this information with a pinch of salt, since all of this is based on speculation.
Nintendo has accidentally leaked their own products in the past, and now that the Metroid series' 35th anniversary is next year, chances are that a Nintendo Switch version of Metroid: Samus Returns could well be on the table; Nintendo will do something for the series' anniversary, we just don't know what.
UPDATE:
It has been brought to our attention that on GistGear's website the "Controller Gear Officially Licensed Nintendo Switch Skin & Screen Protector Set - Super Metroid - Nintendo Switch" has been available since 2018, and they have been using that same image with Metroid: Samus Returns being played on a Nintendo Switch. (Shout-outs to the people over at NintendoLife for the heads up)
The same image can be seen being used for other Nintendo Switch games that are relevant to the products being promoted, so this is pretty much solid proof that Metroid: Samus Returns for the Nintendo Switch has not been accidentally leaked by Nintendo.