There is no question at all that New Super Mario Bros U for the Wii-U was one of the top games on for that particular console. In fact, following release in 2012 the New Super Mario Bros U game managed to reach over 5.8 million units worldwide in terms of sales. The multiplayer 2.5D side scrolling platform game fell just behind Super Mario 3D World in terms of sales and is one of the few titles from the Wii-U that deserves a sequel. While Nintendo managed to bring New Super Mario Bros U to the Switch console in early-2019; there has been no major announcement since then about a potential sequel for the Switch console. However, seeing how successful Super Mario Odyssey has been since its release in Q4 2017 Nintendo may not have any plans on making a New Super Mario Bros title for the Switch console. In fact, we are still waiting for an official announcement regarding a Mario Kart 9 game from Nintendo in the future. Even through, games like Super Mario Odyssey & Super Mario 3D World were bigger attractions than NSMB the game was still too good to not have sometime type of spiritual successor.
Sometimes its hard to believe that New Super Mario Bros U came out in ’12 which was almost a decade ago. In terms of popularity some would argue that New Super Mario Bros U was not quite as popular as its ’09 prequel for the Wii console. The Wii-U in general was not nearly as popular as the Wii console which may have been one of the reasons why it did not sell nearly as much. The New Super Mario Bros Wii game managed to sell over 30 million copies worldwide within course of a decade. It quite that we might see another New Super Mario Bros game on the Switch in near future if the demand among fans of the series is high enough.