Very interesting concept. I like it!
As for the book, which I read many moons ago, maybe the technological changes were unpredicted because the book was not actually about the future. The foreword to the book stated that, although published in 1949, it had been written in 1948. In other words, by switching the last two digits of the date, Orwell wanted to say that that foreseen future was, at least for the most part, actually already present. This idea gave me the shivers ...