Unfortunately, some adult children find out too late that their loved ones did not take all the necessary steps as it relates to estate planning. This can compromise the integrity of what the decedent wanted to pass along particularly if the will was updated but the beneficiary designations on bank accounts, retirement accounts or life insurance policies were not. 
The companies that have those beneficiary designations are responsible for adhering to the last filed materials by the decedent, meaning that even if the will stipulates that someone is to receive half or all of the overall estate, those beneficiary designations are cleared separately. This means that if a person did not update their life insurance policy and a spouse they had divorced from is still listed as the beneficiary, that individual would still be entitled legally to receive any and all benefits under that life insurance policy to which they were previously entitled.
It is extremely important to ensure that your loved ones update their documents on both ends as it relates to estate planning tools like wills as well as beneficiary designation forms including those with life insurance policies. Consulting with an experienced estate planning lawyer can help you accomplish this goal. It is essential that your parents understand that these are two separate things and they both should be updated if they intend to update their estate plan purposes overall.