I am executor of my aunt's estate. She was owner of a life insurance policy (no contingent owner) on her husband who is still alive. I am the beneficiary. Her will stipulates that I am the beneficiary of all of her estate as well. I believe that the ownership of the policy insuring her ex-husband passes to the estate but the insurance company is saying that since he is over 18 and the insured, that he must become the owner. The policy was established when both she and he were adults; he was not a minor.
My guess would be that you got that information by calling a toll free number for the insurance company where you're less likely to get people used to dealing with non-standard circumstances like yours. Them saying he has to become the owner is laughable...why stop at the insurance policy?
If you're the beneficiary of your aunt's entire estate, then, there is no ambiguity. All that was hers becomes yours including this life insurance policy which is an asset just like her car, house of favorite slippers passed to you. The fact that it covers her ex-husband's life is immaterial. However, you should verify it was taken out properly. Since they were married, she definitely had an insurable interest at the time the policy was written, but I believe she would have needed his consent to take out the policy (you'll need to double-check this).
Absent any irregularity in how/when the policy was written, there should be no confusion, although since we're talking about an insurance company you might need to get a lawyer involved to make this point clear and avoid their run around by design.
I should add that life insurance policies are tradeable assets which people sell (I'm only aware of this when the insured and policy owner are the same person) to total strangers who then make the premium payments until the covered person passes (quite a morbid business if you ask me). If you do not wish to assume payments and find yourself in the weird position of waiting for/checking on someone to die, you might be able to sell it for cash depending on your country/jurisdiction (to my knowledge, it is legal in the US, parts of Canada, UK and Australia)