While choosing Azure ad as an identity provider why is OpenId Connect the type prescribed in Okta

Be sure to select Add OpenID Connect IdP as the type of Identity Provider that you want to create for Azure AD in Okta.

Why is this note given in the developer’s docs of Okta. Why would’nt I be able to use SAML 2.0 as the Idp protocol when the app that is registered in Azure is a SAML 2.0 application

Both options should work. I used Oracle IDCS to use Azure ad IdP via SAML.
With OIDC I still have issues since mircrosoft is not the best at implementing standards…
In OIDC when requesting the email claim (default option for linking Okta accounts) it does not return in the id token but in the access token under different claims, a nightmare I am still looking into.

But yes you can use Azure as a SAML provider too.

I know Azure can be used as SAML provider. I’m just doubtful if Okta supports Azure AD federation using SAML as type of Idp. Here I am considering that Azure AD is identity provider and Okta is service provider. I am pasting a link in that regard too.
https://developer.okta.com/docs/guides/add-an-external-idp/azure/configure-idp-in-okta/