Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Joann, I am very sorry for your loss.
I assume you don't know his login credentials at all, right?
If so, like any other services you reached out to, this process becomes a legal process. Microsoft needs to be served court order or subpoena. You said you were in the probate process to gain access to his accounts, does it mean you already sent above documents to Microsoft according to this document? https://support.microsoft.com/en-us/accounts-billing/manage/accessing-outlook-com-onedrive-and-other-microsoft-services-when-someone-has-died
Are you in the US, or a different country?
Also, you are not talking to support here. This is a community forum. If I can have a bit better understanding of the questions I asked here, I can hopefully give you a better answer or point you in the right direction, but no one here in the community can review or access this process. Thanks for your understanding.