I feel like you just jumped to three extremes, who mentioned west Africa or colonization meaning an eradication of language?
West African Kingdoms were put under pressure by the more power Islamic dynasties, much similar to what the Europeans done i.e. indirectly forcing the hand of African Tribes.
You think West Africans heard about Islam and said "fukk our religion we've had for thousands of years, lets jump on this new shyt"
It's funny how people try to justify Islamic imperialism the same way people justify European imperialism.
"b-b-b-b-b-but Africans traded with them, it was all trade"
"it wasnt bad slavery it was the good kind of slavery"
"b-b-b-b-b-but North Africa wasn't inhabited, there was no wars"
some sick shyt!
The greed of man knows no boundaries