I've been using Riot.im for a few weeks, both the web and the mobile client, and...
...it's a pretty damn solid experience! Finally a well-designed, secure, free as in freedom IM that doesn't suck.
Could you all, you know, ditch Slack, IRC, WhatsApp, Telegram and Discord and move to Matrix? Onegai-shimasu 🙏
AFAIK they haven't announced a new name yet. They made a pre-announcment as a warning that they would be making the change soon, and so it wouldn't be a surprise when they announce a new name.
The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!