I think what Brendan is trying to say is that Dart simply had no influence on ES6 and ES7 except for the idea of SIMD. That means no specific implementations, and no high level ideas.

Any resemblance you might find between Dart and ES6/ES7 would be because of Darts resemblance to either CoffeeScript or TypeScript, languages that did in fact influence ES6 and ES7.

My personal view: I don't think Dart is the sort of language Javascript wants to be like at all. Also, totally off topic regarding your comment of 2 years ago: Java has never kept up with C# has always been years behind and still lacks many features that C# has had for ages. The only reason people still use Java is that C# had no enterprise backing on non-Microsoft platforms and its main implementation was proprietary. These things are changing, and I think that will be the end (finally) of Java.