On pg. 117 Johnson addresses hypertext specifically:
It seems almost absurd to think of this now, but when the idea of hypertext documents first entered the popular domain in the early nineties, it was a distinctly avant-garde idea, promoted by an experimentalist literary fringe.... Fast forward less than a decade, and something extraordinary occurs: exploring nonlinear document structures becomes as second nature as dialing a phone for hundreds of millions --if not billions-- of people. The mass embrace of hypertext is ... a cultural form that was once exclusively limited to avant-garde sensibilities, now happily enjoyed by grandmothers and third-graders worldwide.
His observation is absolutely true, and I've seen it personally. In June I taught a sample class for fifth-graders at an elite private school, and in a half hour the class had assembled the beginnings of a website through a wiki. I could not have done that even three years ago.
That said, I think he's being a bit glib. Readers of the web are still struggling to navigate nonlinear text, and mostly do so only to get to the bits that are linear enough to be comfortable and understandable. The 'grandmothers and third-graders' I've watched navigate the web are still more comfortable with a newspaper which has links instead of physical page-flipping than with the multilinear and conversational emergent structure of a wiki.
That said, I think even the translated, less-hypertextual media form a sort of ramp up to the more novel structures, and that's the main point of EBIGFY. The new media start out in emulation, but as they move on to innovate, they bring their readers along.