I don't think MKV is better suited for low-latency streaming production (as opposed to consumption) than MP4. That's really more of the domain of MPEG-TS, RTP etc., and presumably this is a reliable transport alternative to that.

HLS, MPEG-DASH etc. do successfully work around much of that, but they're really mostly that – workarounds to present stream-like semantics over an HTTP + CDN based delivery mechanism.

There are significant gaps on the production/distribution side of things, i.e., everything that happens before the CDN (and for very low latency even beyond), and I suppose this is an attempt at filling those.