All handhelds are hybrid now since they're all copying Nintendo and dockable to an external display. So I feel like the term is pretty much interchangeable at this point.
After comments from an insider, a reimagined 3D Mario game may be more than an assumption. While not offering details, NateTheHate appears to know of a Switch 2 title in development. The leaker previously said a Super Mario Odyssey sequel would rejuvenate Nintendo's slowing console sales.