Egypt already has low latency and good connectivity to cloud regions in Italy (and further afield in Europe), Bahrain, Saudi Arabia, Dubai etc. Meanwhile latency from South Africa to European cloud regions is >150ms. IOW, putting the first cloud region in Africa in South Africa makes sense because southern Africa is the region that needs one the most.
This was my first thought. But perhaps there is less utility in placing this datacenter in Egypt, where it would be relatively close to datacenters already in Europe? I think South Africa probably gets them more bang for their buck, since it's much further from others.