Not only does it remind me a bit of Medium.com’s interface, it is highly reminiscent of Aaron Parecki’s Quill editor which uses the open Micropub spec to publish to the Micropub endpoint on my blog. Though his isn’t as fully featured as the Gutenberg example, he could certainly add to it, but then it could be used to publish to any site that supports the spec.
The nice part about Micropub (and the fact that there’s already a Micropub plugin for WordPress) is that developers can build multiple competing publishing interfaces to publish to any website out there. (Or developers could even build custom publishing interfaces for their clients.)
In fact, if they wanted to do a highly valuable pivot, Medium.com could add publishing via Micropub to their platform and really become the billionaire’s typewriter that some have suggested it to be.