There's something about a horse involved.
Nintendo has apparently developed a sequel to Switch's other launch title 1-2 Switch, but it may never see the light of day.
In reporting at Fanbyte, the title - apparently titled "Everybody's 1-2 Switch" - has been in development since the success of the original which shipped 3.45m copies. In the interest of not making the original game irrelevant, the sequel would feature an option for 100 player play via smartphone (such as with the Jackbox Party Packs and the recently released RiffTrax game). The game-show like atmosphere would also star a host named "Horse" - someone wearing the top half of a horse outfit.
Reportedly, testing for the sequel was so negative that "Different trusted employees within Nintendo were raising alarms that the game released as-is would damage the company’s reputation as a great software developer." Cases for a physical version were created, and some at Nintendo are pushing for the game to come out at retail, though others have suggested adding the game to the Expansion Pack for Switch Online to try and recoup development costs that way.
Nintendo has not officially commented, though several sources confirmed the information to Fanbyte and NWR has been able to corroborate the reports.