We do know that the climate of the Sahara differed and it was grasslands in portions for a time.
But it wasn't farmed (your own article notes that the seeds found were wild), and the processes which re-asserted the pre-existing desert landscape were not human-induced.
Modern humans themselves originated only 200 kya.
<https://ui.adsabs.harvard.edu/abs/2014Natur.513..401Z>
<https://www.worldhistory.org/article/1886/origins-of-world-a...>