Hm, really interesting that you noticed that R1b-V88 was in the Chadic people; who speak Afro-Asiatic. Interesting ... I never noticed this correlation before.
I would say that it is probably very likely the first R1, or R1a or R1b individuals were very likely Negroid; before becoming fair-skinned; during which these haplogroups mutated in Central Asia. Some of the R1b individuals may have stayed Negroid; during which they migrated back to Africa and managed to take an Afro-Asiatic dialect with them, possibly.
Unless, these paternal R1b Chadic ancestors had fair-skin and mixed with the black africans there. But how did the white skin disappear?
It would also explain other mysteries seen in different ethnic groups/races; such as the Finnish having N1c as well as the Turkic speaking Yakuts. (who are clearly Mongoloid and migrated North into Siberia from Lake Baikal, near modern day Mongolia.)
Maybe all haplogroups out of Africa; even the descending haplogroups of Y-DNA F; were still Negroid when they made it to Asia. And then for example; all European/Asian haplogroups. (I1, I2, G2a, E-V13, T, R1b, R1a, J1, J2, N1c etc.) all developed into fair-skinned Europeans (after breeding with each other) during or after the Mesolithic.
(The same applies for the Mongoloid East Asians who carry Y-DNA C, Q, N, and O for example.)