While I think that this is an interesting idea, I'm trying to verify a number of the claims in this article independently and am coming up short. It seems that there was a grouping of various "lodges" for the building of the Strasbourg Cathedral in 1275(ish) which could be considered a kind of grand lodge, but I can't find much more than that.
The Brother-Book of 1563 is definitely interesting, and that fact that it discusses secret grips and greetings is, as far as I know, the first of it's kind. The Strasburg Constitutions of 1459 are also very interesting and has echoes of our current practices (or vice versa). There is also evidence of non-operative royal supporters/members of lodges, but to claim that this is a speculative beginning is really reaching.
Overall, I'd say that it is an interesting idea and deserves consideration. After all, even the early British legends claim that craft came from Charlemagne. Maybe, figuratively, they were talking about the idea of fraternity coming from Germany.