As of Meteor 1.2, you can write ecmascript2015/es6 code in your meteor apps. All you need to turn this on is to add the 'ecmascript' package to your project. I assume the right place for Telescope would be telescope:lib.
When is Telescope going to make the change? Without even doing a big refactor, newer features could be written in the new standard.
Good tutorial on ecmascript2015 here - https://babeljs.io/docs/learn-es2015