OS level voice chat is 100% a software feature that they can patch in.
No. There ain't some magical phone chip needed to send sound over the internet. There's a headset jack on the system.
lol you guys have no idea what you're talking about. Microphone input is hardware driven.
The audio jack needs to be a TRRS type, with the fourth band allowing voice input, in order allow microphones, and the audio hardware itself needs to be properly wired to route microphone input to the interface that receives that information to be processed.
If you're thinking just because phones can do the microphone through audio jack, you should remember that a phones main purpose is to handle voice input. It's already built in every phone to process voice input.
Is the Switch capable of voice input? No one knows, and no one can prove it. Certainly, that third party contraction certainly makes it seem like it can't handle voice input on the switch itself.