One way the US operators could get round this is by having secondary screening at the gate for all passengers.
I have flown as a pax out of DXB in the past with BA and on one occasion all pax were subject to secondary screening at the gate. Airlines can increase the level of security over and above what the airport operator provides, if they choose to do so. Look no further than EL AL outside of Israel.
It would be a rather embarrassing proposition for the Arab operators facing these restrictions to do the same, as it would be a frank admission that the security on their own doorstep has room for improvement.