Maritime insurance doesn’t usually cover some freak weather (acts of God). It is too risky for the insurer to have large amounts of their book exposed to the same event. I’m not sure if this sandstorm counts as an act of God, but $1B to Egypt for a canal blockage probably pales in comparison to the claims that might be made against late-delivery insurance. It is probably those claims which insurers are most worried about, and those claims which they want to dismiss as due to acts of God (but the cause of “ship blocking canal” feels to me even less like an act of God than “big sandstorm”)