Very interesting. I find it important with these things to distinguish between workflow, collaboration, and design tools. Most of what's mentioned in the article are workflow (exporting, plugins, etc) and collaboration (comments, sharing, etc) improvements. Reducing the friction between designers and developers, between agency and client, between designing and interacting, goes such a long way to help teams create better results. Exciting times for interaction design.
Love Zeplin & Sketch! Zeplin really was a game changer for our team's development process, as well. I tend to use UXPin over Invision though :)
+1 for a great Indy based company!
Stating the obvious, but okay.