Reason calls itself Javascript 2030. That's not a completely unreasonable time line for ML languages to go from the small percentage that they have now to being in the top say 5-10 languages used.

React has made the probability much higher. Reason is kinda like JS the good parts + Immutable JS + Typescript + Redux. Plus it works well with React. If your team is using React there's a good chance you'd get a benefit from implementing Reason in a few places with little risk.