GitHub

The GitHub authentication has been patched to use personal access token.

Here how to create a new personal access token: https://docs.github.com/en/authentication/keeping-your-account-and-data-secure/creating-a-personal-access-token

Microsoft

The Microsoft authentication hasn't been patched so its status is unknown.

When does it happened?

An account authentication occurs only when an extension is asking for it.

For GitLens, since the 12 non-plus version, it won't ask for any new authentication.