I am a little curious that the "seven kinds of intelligence" (give or take a few, in recent years) notion has not been mentioned much, if at all, even if just for completeness.... Has that been discredited by some body of argument or consensus, that I missed somewhere along the line, in the last few years?

Particularly in many approaches to AI, which seem to view, almost a priori (I'll skip the italics and save them for emphasis) the approach of the day to be: work on (ostensibly) "component" features of intelligent agents as we conceive of them, or find them naturalistically.
Thus, (i) machine "visual" object recognition (wavelength band... up for grabs, perhaps, for some items might be better identified by switching up or down the E.M. scale and visual intelligence was one of the proposed seven kinds; (ii) mathematical intelligence or mathematical (dare I say it) intuition; (iii) facility with linguistic tasks, comprehension, multiple language acquisition -- another of the proposed seven; (i.v) manual dexterity and mechanical ability and motor skill (as in athletics, surgery, maybe sculpture, carpentry or whatever) -- another proposed form of intelligence, and so on. (Aside, interesting that these alleged components span the spectrum of difficulty... are, that is, problems from both easy and harder domains, as has been gradually -- sometimes unexpectedly -- revealed by the school of hard knocks, during the decades of AI engineering attempts.)

It seems that actors sympathetic to the top-down, "piecemeal" approach popular in much of the AI community would have jumped at this way of supplanting the ersatz "G" -- as it was called decades ago in early gropings in psychology and cogsci which sought a concept of IQ or living intelligence -- with, now, what many in cognitive science consider the more modern view and those in AI consider a more approachable engineering design strategy.

Any reason we aren't debating this more than we are? Or did I miss it in one of the posts, or bypass it inadvertently in my kindle app (where I read Bostrom's book)?

IQ tests verify inbuilt biases of the one doing the questioning. I have failed these gloriously yet got distinctions at uni. Tests per se mean nothing. [I blame psychologists]. As for non human systems they may mimic intelligence but unless they have sentience they will remain machines. [luckily]