Nope. JavaScript is interpreted. Node.js isn't only compiled. Furthermore, shimming is something completely different. ES6 IS TRANSPILED to ES5. Shimming means writing code to give the functionality which wasn't there natively.
Although not in common sense, Node.js is an interpreted language.Node performs a just-in-time compilation to machine code the moment a piece of code is executed first. Just like what HHVM does for PHP execution.