I’m a big fan of React. Mostly because it’s focused one thing and that’s on building components. It’s up to me to decide how I want to use those components and wire them together.
One of the first architectures released for React apps was Flux and Flux is great for managing separation of updating state from the components. I actually prefer it sometimes to other methods.
Another popular one is Redux. Now Redux isn’t necessarily a React-only architecture or library, but I’m sure that’s how most people use it.
This actually works out pretty well for building ArcGIS JS apps. This is of course, all experimental, but I think worth doing some more prototypes and testing to really flesh it out.