I don't think that representation of the Ewell paper is quite accurate, though admittedly it's been over a year since I read it.
Despite being Jewish (would have had different significance later than during his time!) Schenker was a proud german nationalist and in his own words considered his method one of the ways german people could assert their superiority over other cultures.
The Ewell paper is actually pretty clear that schenkerian analysis is technically valid and quite valuable for many purposes. But also that its origins were in an explicitly racist project, and that applying it without understanding that frame could get you racist results even if you didn't intend them.
It's easy to go after this paper because it sincerely uses "critical race theory" vocabulary, but it's a solid contribution to answering the question "why are some fields so incredibly white even if no one intends them to be that way?"
The essay both-sides it, but Ewell's paper is researched and professional even with its flaws, while in context Jackson's response was fairly nasty and defensive, basically just accusing Ewell of black antisemitism.
I've been following this particular one for years (grew up on schenkerian analysis, in a musical family) and I am definitely not neutral on it. Ewell's moral rigidity on this is unpalatable sometimes and I think you could fairly call him a hothead. But the author's description of the conflict is a lot more "balanced" than the conflict itself really deserves. This is essentially an academic raising a painful point within a field that he clearly loves, and others trying to shut it down because of the embarrassment they feel it exposes them all to.
Seeing how the author misrepresents this issue to make their point makes me not really trust the rest of it. I just happen to be somewhat informed on this one.