setting EwsAllowList does not seem to work

1] I setup an Office 365 Developer Site as suggested @ https://docs.microsoft.com/en-us/exchange/client-developer/exchange-web-services/get-started-with-ews-managed-api-client-applications

2] I setup 2 mail boxes

3] Used Powershell and executed these commands:

3.1] Set-OrganizationConfig -EwsEnabled $False

3.2] Set-OrganizationConfig -EwsAllowList @{add='WelcomeList'}

3.3] Set-CASMailbox -EwsEnabled $False

4] Created the sample app @ https://docs.microsoft.com/en-us/exchange/client-developer/exchange-web-services/how-to-authenticate-an-ews-application-by-using-oauth

5] Executed EWS with ImpersonatedUserId = mail ID in [3.3]

Result: I am able to access the list of folders as well as mails in the Inbox

My Assumption : Because of 3.1 to 3.3, i must not get the above result

Assuming i am right, looking for help on where could i be going wrong.