Not necessarily, as he did not include Switch LITE sales in that 14 mil.  Since this is about console and not handheld, he took it out for obvious reasons and the 3DS is not part of the equation.

If we include 3DS, then Switch numbers would be counted at north of 17 mil as LITE would then need to be included as well.

However when it comes to direct comparisons, things are complicated anyway because the Switch alone accounts for both markets.  That said, software is a much better medium to look at.  Overall hardware will look lower, because many people who had a console and a handheld will just buy a Switch this time.  However the total number of software sales should be comparable to what it was when two separate devices were needed for home console and portable gaming.

Shouldn't the Switch be considered the 3DS successor since those leaked documents confirm that it was?

Switch is the successor to both 3DS and Wii U.

Even if that was the original intent, that means nothing because intentions obviously changed leading up to the actual release of the console.  It gets games that typically are seen as console games and sold at 60 bucks, as well as games that you would see on a handheld.  It is a successor to both the 3DS and the WiiU, as it is designed to replace both devices.  It also behaves differently based on whether the device is docked or undocked, with different clock speeds and settings for the games being run.  Even if it did not start that way, that is what was given to us.

Early conceptual ideas mean nothing when classifying what a final product is.  A perdect example would be Halo Combat Evolved.  The game was originally intended to be a Real Time Strategy game, but during its development it changed to a FPS instead.  Would you still consider it a RTS game just because that is what the original concept was, or would you base it on what the final product and call it a FPS?

Are you saying only the LITE is replacing the 3DS? I'm sorry but that is wrong in so many levels. The Switch was already replacing the 3DS long before the LITE existed.

As for the software side of it, I totally agree with you but the OP did not mention software, did he?

I never said that only the LITE follows up the 3DS, you misunderstand.  I said that the LITE has no place in a home console discussion, and therefore he did not count those sales.

If the discussion was about just handhelds, that same 17 plus mil would be used because the full Switch is a successor to both the 3DS and the WiiU, and LITE would also qualify for the discussion as that is indeed a dedicated handheld version of the Switch.

And this is why one to one comparisons don't work well in terms of hardware.  Some people use Switch as a home console only and some use it as a handheld only.  Then you have people who would normally buy both a home console and a handheld, but now they only need one device.  For that reason, total software sales of combined home console and handheld devices compared to the Switch would be a much more interesting measurement to look at with much less wiggle room for bias.

It is basically Nintendo that is doing fine =p

Nintendo carrying Japan on its back, 2021, colourised

At this point it is all up to Nintendo to carry the console market in Japan unless Sony decides to make another handheld. If the next console does PS3 or PS4 numbers then we are in trouble.

I am pretty concerned about home consoles in Japan now if we even have to add the numbers of a handheld device to make them seem relevant.