Not according to the linked study. In fact it's almost the opposite.
> Studies of genetic variation in Africa suggest that even though high levels of mixed ancestry are observed in most African populations, the genetic variation observed in Africa is broadly correlated with geography, language classification ... and subsistence classifications.
> For example, genetic variation among Nilo-Saharan and Afroasiatic-speaking populations from both Central and East Africa ... reflect the geographic region from which they originated, and generally shows a complex pattern of admixture between these populations and the Niger-Kordofanian speakers who migrated into the region more recently. Consistent with linguistic evidence regarding the origin of Nilo-Saharan languages in the Chad/Sudan border, the highest proportion of Nilo-Saharan ancestry is observed among southern Sudanese populations.
> Studies of genetic variation in Africa suggest that even though high levels of mixed ancestry are observed in most African populations, the genetic variation observed in Africa is broadly correlated with geography, language classification ... and subsistence classifications.
> For example, genetic variation among Nilo-Saharan and Afroasiatic-speaking populations from both Central and East Africa ... reflect the geographic region from which they originated, and generally shows a complex pattern of admixture between these populations and the Niger-Kordofanian speakers who migrated into the region more recently. Consistent with linguistic evidence regarding the origin of Nilo-Saharan languages in the Chad/Sudan border, the highest proportion of Nilo-Saharan ancestry is observed among southern Sudanese populations.