Curious, Why does it matter to you?
On the Atom.io website https://atom.io/ it reads "A hackable text editor for the 21st Century". Well I can code in JavaScript 5 and 6. I love love it when a project sticks to web standard, and not have to worry about slangs I don't care about.
> Typescript is great at catching bugs
The same with JavaScript. Google Closure compiler and anyway most IDEs "understand" JavaScript too and catch bugs. JavaScript is dynamically typed not typeless.