It does, but it's mostly for coordinating development rather than a consumer facing product. Personally I'm not convinced Mozilla IM would make sense though. It's a crowded msrket with lots of other options.

There are not many options for a secure, e2e messaging not relying on a single point of failure (including Signal), with a good UX and a possibility of video calls. I only know of Matrix. A AFAIK there are not so many trusted servers.