Earlier quoted context omitted.
Are you sure those are not covered? I know he covers Bloom's filter. And half his treatment on trees is how frequency of access matters on tree creation. (He specifically does not advise just balanced trees.) For hashing, he does cover things at arms length.
All these things only came out after 2000. Basic bloom filter is earlier, but modern bloom filters (and varieties like cuckoo filter) have improved quite a bit. The standard paper on modern bloom filters came out in 2006. It's also true for other areas. Let's take sorting. The best general purpose comparing algorithm is timsort. timsort came out in 2002. Keep in mind TAOCP was originally published in the early 70ies…
Still, your point is fair. The section on secondary key retrieval is very high level. Bloom filters get just two paragraphs.
I think the biggest change in cs is the view towards memory. In much of TAOCP, care is given to the memory footprint. Much of day to day programming is completely ignorant of memory. Scarily so.