It's a tragedy that dictatorships like that one can get away with putting others at risk in that manner. There should be international sanctions against them if they do not cooperate with an independent investigation.
But Egyptians had already filed exceptions form "norms" when agreeing to abide by ICAO investigation rules when judicial investigation were performed. Many other states file similar exceptions.
Sanctions ??"? .there is no such avenue other than not to fly in those states. There of course can be behind the scenes cooperation (identifying shortfalls) as long as it doesn't interfere in an judicial investigations.
The issue to the rest of us is the presumption that the product airworthiness has not been impacted as long as "our" flight operating procedures are followed