Additionally, the pyramids at Giza are ~4600 years old and there is evidence of hundreds of houses in the vicinity. It seems dubious that they went from "no roofs" to the great pyramids in only ~400 years.
It's nonsense. Çatalhöyük had houses 9500 years ago (and there are other settlements of similar age or older). The people there would be unlikely to build houses with strong stone walls and neglect to build a roof.
Agreed. I can't imagine that people with even stone tools wouldn't figure out "hey, staying dry is nice" and make at least primitive roofs. A simple thatched or broad-leaf roof (e.g., palm/banana leaves) is not exactly hard technology to figure out.