Several ES6 features very much resemble the few ways coffeescript syntax differs from older versions of ecmascript. Arrow functions, destructured assignment, string templates.

In context, we were commenting on this:

    .attr('transform', d => `translate(${d.x + 1} 0)`)

which looks pretty similar to the coffeescript counterpart:

    .attr 'transform', (d) -> "translate(#{d.x + 1} 0)"

Five subtle differences, but it shows how the things that are new/different about ES6 are more similar to typescript and coffeescript than ES5.

In the specific D3 examples above, the advantages of ES6 have long been available in CoffeeScript.