Food security is not the same as milk security. Food security is a matter of national security, milk security is not. A country can do quite well with a reduced supply of milk.

In Egypt the cost of weat increased toghether with the price of all other grains. And people need grains (but not weat), so they revolted.

Also, what their agriculture changed for is not very relevant, the root of the problem is that their agriculture does not produce enough value for direct consuption or exchange into food (what made their money worth less, and imported food expensive). Growing fruits probably helped reduce the problem.