Events in Egypt both provoked the scramble for and decolonisation of British Africa. Is this a fair assessment of the British involvement in Africa?
This assessment is not really a fair assessment. It is partially true, but it is rather overstated.
While it is true that Egypt was relevant to the Scramble for Africa, it was not the cause of that scramble. The Scramble can be said to have started far from Egypt when France was exploring the Congo region. This was not related to Egypt. Britain did participate in the Scramble in part to protect its interests in Egypt, but Egypt did not really cause the scramble.
Egypt was also relevant to decolonization. The Suez Crisis of 1956 helped to push Britain out of Africa. However, the move to decolonize was caused at least as much by the changing attitudes of people in Britain and other countries like the US. Being forced out of Egypt did not force Britain out of places like Nigeria or Rhodesia. Instead, it was public opinion that had much more to do with decolonization.