I saw this and got excited but no, this isn't discord voice channels. This is an integrated jitsi meet call. It looks like some sort of prototype has been merged to develop though:
What do you mean it's not discord voice channels? Looking at the screenshot[0] their Jitsi Meet integration is identical, because discord voice channels are essentially voice conference calls.
There's still a "join" page every time before you can actually enter a room. And the participants in the room aren't shown as nicely when you're not in it.
Both are very important for replicating Discord's low friction. Opening a full window when it's just a voice channel anyway is also distracting and increases friction.
[0] https://user-images.githubusercontent.com/48614497/159062202...