Originally Posted by OverclockN'
Ok, great. I was suspecting that, but had a hard time proving it. Thanks!
Think of it like this:
NSMB Wii = Super Mario Bros
NSMB U = Super Mario Bros 3 (Its not really a sequal, but its kind of like the "This consoles version of the side scroller Mario platformer"
NSMB U Deluxe = Enhanced Wii-U version ported to Switch.
A lot of first party Wiii-U titles have been ported to Switch...so its actually best to get the Switch version of those games as they're likely enhanced/improved in some way.