Yes, based on replies on Twitter, the "NEW MAGIC" is almost certainly something like "reactive ActionView::Component". ActionView::Component didn't make it into Rails 6 but will likely land in 6.1 and this news from DHH makes it seem like they're going to support some kind of real-time piece a la Phoenix LiveView. The current Rails-land answer to this is Stimulus Reflex but it falls short in a number of ways and I'm not surprised Hey didn't use it. We ended up releasing our own version of this paradigm (put simply, HTML over websockets) because we thought the Rails world needed a proper LiveView incarnation.[1]
[1] https://github.com/unabridged/motion