But this is where it get even more insidious, but bear with me to the end here. If you're an older teenage or an adult buying the Switch, meh whatever. But if you're buying one for your young kid, well... you're gonna need two phones...
It's a paid phone app, which means it will require parental permission. So the parent will do that on the kid's phone. And if that's the case, why not have it connect to the master app account on the parent's phone as well, for further verification?
The trap is set. Because now you have an app that is directly connected to your kid's app. You can see when they log on to Switch Network, what they're playing, etc. Even more, if they're chatting via voice or text. That last bit can't be done on XBL or PSN easily, if at all, but Nintendo's method makes it completely natural.
And now if that's the case, maybe the app will let you see their texts, or hear their conversations in real time, or even transcribe their voice into text, if Nintendo is renting voice-to-text capabilities from Google or Amazon.
I KNOW but it's not that crazy; remember last gen some sports games used to fire players from their single player coaching because of profanity over the mic.
Of course, this could all be way past Nintendo's level of care, but hey.