Well, you kind of made it sound like he was predicting it wouldn't be found for a century (though I suppose is he'd written the book just 4 years earlier, he'd then be right).

It actually goes into some detail about why the Higgs boson is important, it just says "it hasn't been found yet". If you fill in the epilogue of "the Higgs boson was found in 2012" yourself, those pages are still consistent, correct and useful.

It would really be out of date if the Higgs had been disproved, as it would have two pages of, essentially, a branch predictor failure.