[1] Chatting with avatars that can navigate in a 3D digital environment, with or without an actual VR headset. That's just like the eponymous VRChat which allows 2D users to interact with 3D users and vice-versa. I highly recommend trying it. It's free and the worlds are beautiful. https://vrchat.com/
Think about the really controversial tweets that garner thousands of responses. What if there was a link next to the tweet that launched you into a virtual lounge where you can interact with other people looking to discuss the tweet? If someone who joins one of those groups wants to summarize their thoughts and conclusions from the discussion afterwards, in an async format, their response would indicate which discussion group that they were in. It would also be bundled with posts from other users in the same discussion group. It would be like "Twitter meets Reddit meets VRChat."
I could see it being useful as something of an intermediate between traditional online video games and offline gatherings involving food & boardgames. I don't see it being used as a primary mode of communication though, for the simple reason that it demands too much time and attention. Text messages and email occupy that space because it's so convenient to pick up and drop them at any time, even with a half-read message or a half-written reply. With VR that means putting on your gear every time, and resuming the "VR video" or whatever.
Heck, tons of people complain when video talks are posted without slides/transcripts. They want the information. They don't care about any other aspects of the presentation. VR in that case just seems to be more distracting stuff that gets in the way of the information.