Ah, I didn’t know that. I’m not sure I consider that “great support.” It looks relatively new, and from the blog post it seems the spec is still in proposal and development stage. It’s not implemented in any of the chat clients either.
Well, it's 'great support' in that i use it as my daily driver instead of Jitsi without problems. The spec is indeed still in proposal, and it's currently being integrated into Element Web/iOS/Android. Meanwhile Matrix has had native 1:1 VoIP/Video calling since 2015.
Excited to know it’s on the way though.