Ionic 2 with ES6 or TypeScript

Hi!
I started a new Ionic 2 project for testing purposes.
So, after looking at the source files, I saw that Ionic 2 comes with ES6 integration which is not exactly the same as TypeScript.
I just want to know if ES6 was adopted by the Ionic Team in place of TypeScript.
Anyway, Ionic 2 will be awesome! Really nice jobs guys!
Regards