Confirmed
- Online voice chat and lobbies is through a smartphone app
- Connect your own ear buds to your phone to do voice chatting through the app. So it looks like to chat you have to use a earpiece that has a mic, or leave your phone on speaker mode
- Will be a paid service later on
So it looks like Ninty is trying to shovel the interface to your phone, and you tie up your phone chatting on Switch. While Reggie is promoting it as a great idea, it seems to me like they did this to save on the system's HDD and OS ram usage.
By the sounds of it on GAF, in order to do MP stuff with gamers chatting, you have to do the smartphone app way. It doesn't look like you can do it on the system/tablet itself by plugging in a headset into the tablet. You have to do it all with your own phone beside you.