"All APIs can benefit from API management, realtime or not." Amen to that! :-) It's good to see this kind of thing coming to realtime, although it's kind of sad that some of the backend services mentioned don't have support for WebSocket yet...
Realtime is still a fairly new concept in the world of API tools. The realtime APIs most of us know about (e.g. Twitter, Dropbox, etc) were all built from custom infrastructure. We'll get there. :)