How do these early theories of African history still affect western views of the history of black Africa and its peoples? ...

Much of what ends up coming out of the video clips is the
notion of how imperialism and colonialism impacted the narrative of African History. 
The difference in perception between both Western History and African History is
revealed in the oral tradition of historical development.  The fact is that imperialism
had a detrimental impact on two levels.  The first is that those who were the torch
bearers of this history were wiped out due to old age, enslavement, breaking of
villages, so that this history never went on a formal record.  In addition to this,
enslavement and the displacement of slaves from Africa made its historical tradition
impossible to pass down.  In the end, Western thought for a long time believed that
there was no history to Africa because it was never "on record."  Consciously or not,
Western thought did much to destroy this historical record through its actions that
served to silence and served to negate African History.  I think that there is a general
consensus that suggests this is not the case today.  The opening of the first video
where an Oxford History Professor would claim that there is "no history to Africa" is
not something that would be suggested by even the most novice of professionals today. 
There is a general understanding and acceptance that Africa's history became profoundly
skewed and distorted by the West and that there was history even before the West entered
into African historical consciousness.  We now know that we can obtain a great deal of
historical detail on Africa, removing its label of the "dark continent," through a
simple search that integrates the role of the West in the process of African historical
identity.