My take on the glossary, with the caveat of "I don't know man, I wasn't there" :
Yeah, it's still solid. The concepts themselves didn't change that much from the early discussions to their use today. But the glossary is really full of stuff that was The Big Thing™ at the time but actually it wasn't that big, or at least in that form. KFD, GNS, IIEE all got refined in less "boxes to put stuff into", more "effective systemics" ways. The good discussion these days seems to move away from acronyms and taxonomy and toward predictive and descriptive systemics.
EDIT because I'm clear as mud: take GNS. For a time, the whole of discussion was "what are the different creative agendas?" and all in all it was pretty inward and definitive, once we're done we're done.
Now it's more "so, creative agendas, what's it good for and what can we do with them?" and that discussion is outward and open and that's what design's really about, in a sense.