The publishing of the PageRank algorithm was the wrong milestone; my bad. The important milestone was a less well-defined point when search engine users and competitors realized that Google was disruptive.
PageRank was the way forward but the true schlep, in the Paul Graham sense [1], was the brute force continuous hardware scaling required to keep up with the growth of the Internet. DEC needed a technical pivot first and foremost. I've seen no evidence that the AltaVista team understood the technical challenge but I could be easily convinced that bean counters and/or management stifled a promising response; absence of evidence is not evidence of absence.