Hmm, an Airbus disappearing suddenly during cruise? Where have I seen this before?
Imagine a jigsaw puzzle with six pieces.
1. Egyptair.
2. In the Cruise with no abnormalities.
3. WX good.
4. France/Egypt.
5. ISIL Threats towards Egyptians/Westerners.
It doesn't take a genius to figure out the likely sixth piece. It also doesn't take a genius to know the Egyptians will deny it till they are blue in the face (much form in the area).