Apart from this, could you elaborate a lil more on other use cases for a messenger which can hold conversations on a temporary basis?
Selling things or more transactional things. You have to meet-up somewhere to exchange the item. Having real time messaging would be helpful here.
Conferences themselves. Or hackathons. It's important to add everyone you meet at the conference or hackathon on linkedin. But at a hackathon, for example, you're going to be talking a lot to a small group of people. Real time messaging might be super important there. And then afterwards only reach out once in awhile.
And online mobile games. I play a lot of those clan based games. And their native game chats are usually awful, clunky, slow, I lose messages. There's also a good amount of those people I don't want to give my real info too but I still want to chat off the game. The major case is if there's drama in the game and I need to send a screenshot over for one reason or another. This has happened to me a lot.