No, they kept PHP for the backend, and created a new front-end with node and JS. And that's just for the admin pages.
>If they're leading by example, we should ditch WordPress.org and PHP in favor of node.js web apps and frameworks too, since it's the way of the future?
Perhaps. Do you expect Automattic to tell you what your stack should be?
Besides, if node/Js is the "way of the future" then there's no need to ditch "wordPress.org" since it has already embraced that future.