I am unable to manage a deceased son Apple devices

Were you able to provide court documentation?

The article linked by den.thed also says that court documentation may be required. The purpose of this court documentation is to show that the Will is valid and there are many things that a court must consider:

• Was it prepared by an Attorney? This may not be required, but there are many different rules depending on the region or state you live in. There are many places online where you can get templates for a will, but some will have to be notarized or entirely handwritten in the persons handwriting along with witness signatures.
• Are there multiple wills?
• Has the Will been recorded with the courts?
• Is anyone challenging the Will? If someone wants to contest the will, they will file this objection with the courts.

These are not easy matters that Apple can make a determination and must rely on the courts to provide direction. Each State or Region will also have different rules that Apple is not familiar with. I am sorry you are having to go through this as it is always difficult.

Sorry for your loss.

Have a look at > How to request access to a deceased family member's Apple account - Apple Support