This type of semantic hair splitting and manufactured outrage helps no one. OK, instead of pre-colonial, use pre-European. But, look! The rose by another name smells the same.
Absolutely. The author is WAY too hung up on the phrase as some kind of holdover from colonial-era European writers using it as a pejorative to mean "uncivilized", when now almost anyone you'd ask would interpret "pre-colonial" as meaning, "before the racist, white supremacist European assholes invaded".
If someone is actively using the phrase to homogenize African cultures or treat pre-colonial Africa as a monolith, call them out for the homogenization; people do that with "post-colonial" Africa too.
I think the point might be reasonably condensed to:
Africa is big and diverse, and its internal geographic barriers (particularly the Sahara) are more significant than the ones dividing it from Europe and from southwest Asia.
Some parts of Africa have thousands of years of written or otherwise well-documented history, and each part has seen several waves of significant change, including colonization from other areas of Africa (e.g. by Egypt or Mali), from Europe (e.g. by Rome), and from southwest Asia (e.g. by the Umayyads); and colonization of other areas (e.g. of the Iberian peninsula by Morocco).
For some parts of Africa, the latest round of European colonization is arguably less significant than previous changes.
Thus, for serious discussions of history, "pre-colonial Africa" is not a useful division to make: you won't be able to say anything meaningful without more precisely specifying the time and region (e.g. "medieval west Africa").
This isn't fixed by changing to "pre-European Africa".
Both "pre-colonial Africa" and "pre-European Africa" additionally suck because, instead of using a more relevant division, you are using a less-relevant Eurocentric term.
I think you did not understand the point of the author at all. Using pre-European would just be as bad as using pre-colonial.
It does matter a lot actually in what framework we talk and think about things. I think the author made a good job of explaining why setting everything in Africa's history in relation to this one event of colonialism by Europeans is ignorant and incorrect.
You may have notized that the author didn't give any alternative to the term per-colonial and for a reason. Just using another term would defeat the whole point of trying to abandon the faulty framework behind the term. We need to get rid of thinking about Africa as unimportant, homogeneous and uncivilized. We need to get rid of our ignorance and biased views!