I read that a day or so ago. It's absolutely CR

ZY that a cruise line's travel insurance didn't cover someone for delays due to airline issues. I've always thought that that's one reason to buy airfare and a cruise together (I've never taken a cruise and so therefore have never bought airfare with a cruise).
I read through the fine print, and it turns out (and Aon confirms) the travel insurance portion does not provide reimbursement for a cruise if airline issues cause a traveler to miss it. But under the Cancel for Any Reason component, it looks to me as if Norwegian should have given you that credit with no hassle.
FWIW, the "cancel for any reason" insurance here provides a 75% credit, not a refund.