Most definitely. I see them releasing SCD for NX in 2019 or so in order to boost it up to around the level of PS5 and Xbox 4 which will likely release in 2019 so that NX can keep getting 3rd party ports. Eventually they'll need to release a new console though, SCD can only boost NX for so long. I don't know about hardware every 2 years though, that's pretty fast, at least for the console, handheld might need an upgrade every 2 years so it doesn't fall too far behind smartphones and tablets, but with game support lasting for 4 years.
If they release a new NX it will most likely be like the new 3ds. The new 3ds is amiibo compatible so if a new NX is released it will be compatible to handle more SCDs imo.