What happens to life insurance if someone dies but is not claimed?

My dad passed away a few years back without a will and his estate went into probate. Mother passed few years prior. I was the administrator of his estate and had closed and paid out all assets accordingly at the age of 24 to me and my siblings.

After 2 years, one thing still bothers me-what if he had life insurance at the time of his death?

I did all my due diligence during probate, getting access to his email, looking at bills, asked his previous employer and was not able to find any “active” policy. I even made claims with the state insurance office to do a search for him and didn’t find anything active. The state report did note either previous inactive policies or terminated policies. My probate attorney was also unsuccessful in finding anything.

Years later I have thoughts, what if there was a policy out there but we couldn’t find it.

If he did have a life insurance policy, and did pass while it was active, he would have not paid his premiums. Could the policy issuer have just cancelled and end it? Are there laws for what needs to be done such as their due diligence/outreach? Does it turn into unclaimed property, etc?

Since the estate is closed after probate, I know insurance is payable upon death, which probate isn’t needed. I want to make sure even years later that I 100% completely exhausted all my resources in determining if one was even purchased. Heck, he probably canceled it before dying and im just trying to find an excuse to find closure.