For good or ill, it's not going to happen. ES6 is meant to have a VERY small promises API (although you can use a library like Bluebird as a wrapper around the native implementation to provide a better API). A more full features promises API will be coming in ES7.
See, for example, the discussion about adding a .any() method to the ES6 promise spec: https://esdiscuss.org/topic/promise-any
The conclusion basically that yes it would be useful, but it'll have to be ES7 not ES6.