Nintendo definitely have plan concerning new console, were you thinking that they don't do R&D on HW?Nintendos plans to potentially releasing a new console in the coming years?
Releasing something requires that it's meets certain standards and these standards can change due to market condition. At this moment those standards are likely to be very very high so the R&D team can't meet it no matter what they do. If Nintendo is under pressure then those standards get lowered.
When standards are high the likes of joycon will never be released. (it's a piece of shit and really lowered my opinion of Nintendo)