Nope. I could see Nintendo abandoning their home console hardware before handhelds.
Say what you want about smart phones eating handheld sales but IMO there is a large enough group of consumers that want dedicated gaming handhelds to keep it going, especially if it's just one console.
Sure, smart phones ate up DS and PSP - 3DS and Vita sales numbers but not as much as PS4 and XBox ate up Wii U sales.
Direct competition will continue to hurt Nintendo much more than indirect competition so abandoning a platform where there is no direct competition would be stupid.