To add some more context. Microsoft (and a lot of tech companies) have a relatively big presence in Israel, and that includes a lot of Israeli employees and acquired business.

When you’re a star, they let you do it.

I’d say the purpose of the feature is to do as intended, ensure the documents authenticity and integrity. The mechanism still requires people trust your signature (public key), so you need another strategy to establish that trust. If you wanted to share a confidential document to a person you know on discord, and they already trust your discord profile, you would need to use said profile to get people to trust the key you’re going to use, belongs to and identifies you. This really isn’t different from third party Cas, just a lot of certificates from them are already trusted by default and part of the internet wide key infrastructure.