We had a cruise for 2020 that I cancelled before the cruise line (Princess) inevitably cancelled it. We not only got back our refundable deposit, but also the 3rd party insurance, but only because of a ruling by the NY State insurance commissioner. Our TA told me when I asked him that no other state has such a rule.
Another time, almost 20 years ago, a river cruise from Amsterdam was chartered out from under us after final payment. We decided to fly to Amsterdam and book a hotel instead. The insurance was transferred, and because the cost was now less (we went for less days and obviously meals were no longer included), they not only transferred the policy, but gave us a small refund (which I had not expected.)