I think I wrote that part of Black Genesis, so yes, I think that is correct :-)
But, you will notice that it is different, although similar to, the date I suggested in The Origin Map. That is because in The Origin Map I was entertaining the possibility that the "anchor" or "start point" for Zep Tepi might be the northern culmination of the Galactic Center.
Whether one chooses, northern culmination of Galactic Center, OR southern culmination of Sirius, OR northern culmination (and pole star status) of Vega, OR best fit of Orion's Belt to the Great Pyramids, OR equinox sun moving into Leo ... each of those will yield slightly different dates for Zep Tepi, but they are all in the 10th to 12th millennium BC range.
I am not dogmatic as to which of those I prefer to label as THE ONE. In fact, I think it could be more than one of them. Such that by the time circa Old Kingdom Egypt, the religious-cultural notion of Zep Tepi may well have included more than one of those five astronomical measures, and may have been thought of as roughly in the 10th to 12th millenium BC time
...Or, maybe the Old Kingdom priests did believe in only one precise specific date for Zep Tepi ... I don't know.