Actually there is direct archeological evidence since 5th millennium BCE, including cattle and pottery - which would all line up with the Mediterranean EEF hypothesis for V88: https://en.wikipedia.org/wiki/Tenerian_culture
I hope they get aDNA from there eventually. Word is they are trying, but were not successful by now.
There's a complete absence of material until the middle of the second millennium BC, when the Gajiganna Neolithic appears. These people as you would expect are extremely tall and have West Arican/Nilotic morphologies. They settled the region, so for V88 to be local they need to have had it already, otherwise it's an Iron Age to Medieval introgression. I strongly doubt they did, because there's no discernible correlation between haplogroups and language. An Ojibwe dynamic between Neolithic population and an invading Iron Age one seems more likely.
V69 implies that there must have been a post-Neolithic movement. Africa-> Arabia or Arabia -> Africa.