I can't speak for OP, although I basically agree with you and OP simultaneously.
However, look at it as an optimization problem. CC testing standards and format may be ideal testing tools for 49 minutes 5th period after lunch 5 days a week in a 40 person classroom, performed in perfect lock step by all 40 students, only failure mode is repeating the entire class or developing a hatred of the topic, aka standard public school experience.
However, what does "alignment" WRT KA mean when the educational experience has completely changed? Its analog, you can watch a video 50 times will you get it, jump back and forth, all that. I'd propose the "best" testing technique for that environment probably looks a lot like KA and not so much CC because you need instant feedback and simple questions. Its not quite as good as personal 1 on 1 tutoring, but its better than sitting in class, more importantly the experience is inherently different than sitting in class...
The proposal in the linked article seems to be that KA epic fails, solely in "alignment", because it doesn't test like CC, which is trivial to test and prove and analyze statistically. Factually looks like a good study. Maybe it fails the relevance test because "alignment" is fuzzy to me (maybe it has a special jargon meaning among CC teachers?) I think MAYBE OP and I are concerned that KA aligns pretty well to a decent curriculum (CC) WRT topics and order of topics and presentation standards, and I hope KA doesn't ruin the KA assessment portion to better match CC assessments solely to get a checkbox somewhere.
Maybe we can abstract out KA from the discussion. I'm tolerably good at math and have tutored people. If you define alignment with CC as slavishly following their assessment technique at all times even though I'm 1 on 1 in an ongoing human conversation, such that everything I speak must statistically match the CC assessment percentages in style, tone, and technique, that's ridiculous. If you defined alignment as I'm talking about sets of linear equations with infinite solution set the same general time, order, and way the CC talks about it, thats OK, even if I assess a tutored student the "wrong way" by asking the wrong type of questions (which may very well be the right question for that kid at that moment while also being on average the wrong way to teach all American Kids in a 40 person classroom)
Its seems reasonably non controversial that CC curriculum and assessment are local maxima on society wide averages for teaching math. It seems reasonably non controversial that KAs assessment tools seem to be a local maxima for computerized delivery of help to kids that need extra help. I (and possibly OP) don't think it reasonable to trash talk KA because the local maxima of effectiveness for society as an average whole in a classroom setting doesn't necessarily match KAs local maxima of effectiveness for "kids who need help at home". The danger is screwing up KA enough to make it useless for the kids who need it after school, just to achieve a marketing checkmark.