Takahashi said:
…“It is Nintendo Switch, so maybe we’ll switch it up!” jokes Takahashi, responding to a question about whether Switch’s life cycle will resemble more the company’s TV consoles (completely new ideas at five-year-plus intervals) or its handhelds (subtler changes every few years). “Certainly, we’ve designed Nintendo Switch in a way that it can be used by consumers in the way that best suits them. I think we may see that people who have bought a Nintendo home console in the past traditionally, they may treat Switch like a home console and buy it and use it for a long period of time.”

“Whereas people who have been traditionally Nintendo handheld gamers, they may buy Nintendo Switch and then for example, if a new version were to come out later, then maybe they would decide to upgrade to that…

Kimishima said:

Consumers purchased Nintendo 3DS systems in numbers we expected last fiscal year. It has  an  ample  software  lineup  at  a price point that makes the system affordable especially for  parents looking to buy for their kids . We expect that demand to continue during this fiscal year  as well, so we will continue to sell the product.

Given  that  Nintendo  Switch  is  a  home  gaming  system  that  can  be  taken  on  the  go,  this situation may change if  it  grows  from  being  a  one -per -household  system  to  a  one -per -person  system.

But the price of the Nintendo Switch is not something with which most parents would buy a  system for every one of their children in a short period of time.

Moving forward, we will work to  ascertain  what  kinds  of  play  people  want  at which price points,  and  as  long  as  there  is  such  demand,  we  will  continue  to  sell  the  Nintendo  3DS  system.  I  see  the  product  coexisting  with  Nintendo Switch at this point in time.

trent44 said:

...Nintendo knows that the 3DS will fade as Nintendo Switch grows, and they need to fill that lower price entry point to expand the platform significantly...

...Will Nintendo make Nintendo Switch models with newer and better SOCs?
Probably so, but the performance benefit will be marginal to non existent at best, as the focus will be to reduce cost of the total cost of materials
(i.e. a 7nm SOC would allow them to put a smaller battery, reduce the entire chassis size, and remove the active cooling)...

...Nintendo's focus is it leverage its software library to sell its hardware, and to reduce costs of hardware while addressing a wider audience. Focusing on CPU and GPU power and splitting their user base is not where they will expand and Nintendo knows this...

Because Nintendo always had low price and high price point offer on market, Switch with its price point of $300 is high price offer, 3DS with $200-80 is currently low price offer, Nintendo handhelds always had low price point and thats why they were selling like device per person (for instance family with more kids will much more likly buy several Nintendo handhelds for each kid if price point is low enugh), and when 3DS dies Switch will still have price point that will be above $200 (probably around $250), they will need $150-200 Switch offer when 3DS dies. 

Less parts, less tech, smaller form factor, package...means less costs. Of Course that smaller Switch, smaller factor size, smaller screen, without dock, built in controls instead of detachable Joy Cons and whithout some features from Joy Cons, whithout parts need for playing in docked mode, HDMI cable,  smaller package...all means much less cost. So yeah, I think that all that could cut down cost for around $100 compared to regular Switch. 

Switch Mini/Pocket just for handheld play like real replacement for 3DS price point just make too much sense,  and I think we will see something like maybe even next year.

Because Nintendo eventually wants Switch to become a one per person system along with attracting more kids, families & budget conscience consumers.