When I first configured the new version of ConceptHQ Accounts to federate with Microsoft account using OAuth I used these two endpoints which I picked out of a sample.
It resulted in a slightly jarring user experience as we switch from the new look sign in page to the old style permissions page.
However, by switching to the new OAuth 2.0 endpoints
We get a much smoother experience as the styles between the sign in and permissions page remain the same.
Much better. First impressions are important - one style change from your app to your identity provider’s is enough :)