I believe that the Flux architecture was designed to make everything a one-way flow. In the video explaining Flux (at this specific moment: youtu.be/nYkdrAPrdcw) an engineer shows that an application that uses Flux removes all of the complex communication between views and controllers. An global event system would bring back all of the problems that Flux is trying to prevent I believe.
I have had slight experience with Alt, a Flux compliant library which is great to use. It might provide some of the functionality you're looking for. alt.js.org
Note: I don't know a whole lot about React, I'm still learning myself.