Hello,
for email channels
you can already set up an OAuth app
according to these instrutcions:
https://admin-docs.zammad.org/en/latest/channels/microsoft365/index.html
Then you can set up a M$ 365 Mail account
in Zammad
https://admin-docs.zammad.org/en/latest/channels/microsoft365/accounts/account-setup.html
For the notification system you might need to add a to this feature request as it does not support other auth methods as of now:
Best,
Skip