You know what'd be even simpler? Just playing the game online and being able to talk to them in the game!
I don't know how this Discord app works on the phone but I imagine it's still pretty simple. I imagine you get little notices that someone in your Discord friend's list or whatever has logged onto the app. At that point, the app lets you lobby-up with that person.
Well, the message I'm getting is that Nintendo does not see the need to include a more intuitive voice chat feature into the Switch. My guess is that they have no real plans or expectations to get killer multiplayer games where voice chat can be a highly desired feature to have, aside from Splatoon. So they aren't expecting any battlefields, CoD, or the likes any time soon or at all. I'm sure splatoon players won't really care (based on the respond from bans, they never user voice chat anyways) but it's still kinda telling of some of the sacrifices they made for the sake of their price point/portable design)
EDIT: You talked about convenience in your other Switch thread, this isn't very convinient.
No, it isn't which is why I'm encouraging people to forgo this convoluted set-up and just use a third party app for voice chat. I'm sure there are some available on iOS or Android. Until recently, I didn't know what Discord was but apparently, it's a gaming voice chat service or something. I'd look into a phone app for that service if I cared about voice chat.