Happy raises an interesting legal point which has been discussed in various forums without, IMHO, final resolution.

You get the award ticket for free using miles (although miles do have value) and pay for taxes, perhaps airline fuel and close in booking surcharges paid with a card. Do you get the "insurance" benefits of the card you would get if you were paying with dollars, not miles?

The answer likely varies between card issuers with Amex, likely, the most liberal. If someone has actually called Amex or another issuer and gotten a solid answer it would be interesting to hear about.

Meanwhile, as Happy suggests, you can buy an independent policy. I wonder if they would return your miles if you cancel the trip?