I know this thread is old and I haven't read all through the threads, but I just wanted to offer this for those who are still focused on the thread topic. The question isn't about solely did the Egyptians migrate from Egypt, but more so what ethnic groups travelled from the lush Kayinga (Sahara) during desertification to repopulate the Nile Valley to become Egyptian civilization?
I suggest that many people get these works by GJK Campbell-Dunn:
African Origins of Classical Civilization
Who Were the Minoans: An African Answer
You'll see how we moved from the Sahara into Italy, Crete and the Nile Valley. I also recommend Martin Bernal's Black Athena Vol. 3: The Linguistic Evidence. Also look up articles by Dr. Clyde Winters who deals heavily with Saharan migrations into Europe and the Nile Valley.
There is a book coming out Black Genesis by Robert Bauval which will focus exclusively on this. Most of the scholars I've quoted are European Whites. I did this to demonstrate that the scholarship is slowing changing.
link removed so that I can post this reply.
So now you have to get the book by Catherine Acholonu titled They Lived Before Adam and The Gram Code of African Adam. Then you'll be able to see the relationship Egypt had with west Africa. Many people think PUNT is in Ethiopia. That is not the case. PUNT is in Nigeria/Cameroon. And she supplies ample evidence to support this.
So there is an array of evidence out there that west and east Africans knew each other well and that's why when the invasions and droughts came, they knew where to go.