Legacy contact process for Apple ID purchases

My mother recently passed away and my dad is her legacy contact. There doesn’t seem to be a detailed explanation that I can find that explains how this process works past providing the key and death certificate. They were connected as a family. My dad is concerned that by beginning this process he’ll lose access to everything she had purchased (movies, music, etc) because that was all done under her Apple ID.

As a legacy contact, does all her purchases transfer to his Apple ID or does something else happen? Maybe he is better off keeping her account open? He has the password to the account.

Just looking for some direction.

[Re-Titled by Moderator]