Yes. Because of how rapidly Javascript is moving, they want it to be more modular in its releases instead of waiting multiple years in between.

I think that's the plan. Whatever the committee can agree on and ratify by December 2016 will be dubbed "ES 2016" and so on.

Yes, though as I understand, none of the later ones should be as big as ES6/2015. You can't accumulate that many changes in a single year.

It's a bit like WHAT WG's change of HTML5 to HTML (the "living standard"), but less drastic.