Endpoint requested_reviewers doesn't return all reviewers

Endpoint : /repos/{owner}/{repo}/pulls/{pull_number}/requested_reviewers

If the PR has 4 reviewers: A, B, C and D, and A has approved the PR, B has requested a change. Now the endpoint (requested_reviewers) only returns C and D. Is this the expected behaviour? How do I get all the reviewers of the PR?

I am using

/repos/{owner}/{repo}/pulls/{pull_number}/reviews

coupled with

/repos/{owner}/{repo}/pulls/{pull_number}/requested_reviewers

to get the full list of Reviewers of the Pull Request.