Humanities & Cultures

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.