You are SO dead on Heidi. Yeah, I get it, she ain’t black and that offends. Like the kid in the movie, Soul Man (C Thomas Howell — https://en.wikipedia.org/wiki/Soul_Man_(film) ), she can choose to not be black and is taking advantage of what s/he perceives as black privilege.
What Ijeoma Oluo doesn’t get, and you do Heidi, is (Rachel or whatever she’s called) perceives herself as “other” and took on the identity of black (a clear and virulent form of “other” in our society and world) as the closet match to the otherness she feels; so her “other” isn’t nothing…. So her other-feeling has SOME label (god how we can’t stand/tolerate no-label-ness/ambiguity/uncertainty).
There are SO many forms of “other” and we all are so intolerant.