> shouldn’t music history writing and teaching be done in the same backwards direction?
No, that doesn't follow, because we are now talking about obligatory learning of the rest of Music History, which will be what I just experienced for most of the author's text: An endless litany of names, names, names, names, names, some arrows drawn between them, some dates and places attached.
It doesn't matter which order you teach me all the rest of Music History. It doesn't get better that way, although it probably doesn't get worse, either.