I've actually recently designed a concept around the interest graph of Twitter that I think would be a step in the right direction.
Twitter Rooms: https://medium.com/@danielrakh/twitter-rooms-e6f34e843e9a
Twitter Rooms: https://medium.com/@danielrakh/twitter-rooms-e6f34e843e9a
You'd have to find a way to sell this as something different than IRC, because I doubt the idea of "IRC on Twitter" has never crossed Twitter's mind. What differentiates it other than being hosted on Twitter?