I think you’re right in that developers will continue to migrate to static sites, and GitHub in particular, for good reason. But the mass of users that comprise that target market of WordPress isn’t developers. They keep the wheels greased and the gears turning faster and faster for the WordPress world, as an open-source piece of software, which is WordPress’ biggest strength. But WordPress isn’t really what most users want or need, really; it’s just sort of the best available and what’s risen to the top as a matter of timing, momentum and incidentals. That’s why I believe Medium is the true competitor that WordPress needs to be watchful of. And I know they are, because they emulate, to use a nice term, what Medium does for the user experience. But WP can build all the Calypsos it wants; it’s not going to ever be a “Medium” blogging experience, which ultimately will win out over being able to choose from among a kazillion plugins and themes.