.... you do realize that you don't actually know at this point that the Switch plays the "full Nintendo ecosystem", right?
While it is not 100% confirmed or been explicitly stated, I'm not a child and can read between the lines.
Merging the handheld & console divisions for both hardware & software in addition to releasing a device that acts as both a handheld & a console makes it pretty obvious that the whole point of Switch it to release a single device that recieves the full software output and functionality of the two previous ecosystems.
So while it is technically possible that Nintendo will release another device that has its own unique features and software library, the chances of that are about .00001%
When the herd loses its way, the shepard must kill the bull that leads them astray.