I agree with most of this, but one should not overestimate the impact of general hardware progress since 1997. Each extra ply takes an order of magnitude more computation, and the state of the art in endgame tablebases has "only" progressed from 5 pieces (e.g. KBB vs. KN) to six pieces.
I would think that this is parable rather than history. Some of the giveaways are the dig at "operational research" and the mention of the DoD (which a meticulous writer like EWD would have known did not exist until much later).
