I did book the insurance with my husband deployed our dates are "good" but something could always happen with him not getting back in time....SO, I specifically asked about the military and this situation, and was told YES, IT WAS COVERED.....I got the hardcopy paperwork from the company that provides this insurance and IT DOES NOT cover anyone on Active Duty or anywone who gets called up for active duty. SO, I was waayyyy past my date that I could cancel, but Disney did take it off, no questions asked, and an "I'm sorry we provided you with incorrect information". I was very pleased with the way Disney handled it.
Sorry, not trying to tread jack but I thought since there are others who are out there in my situation they would want to know.
I also think that you can cancel the insurance within 14 days. (I think)
Jennifer