GitLab CI/CD for Bitbucket repos, build status

I’ve read the documentation on GitLab CI for external repositories. What the documentation doesn’t mention, though, is whether it writes to Bitbucket’s (or GitHub’s) build status API so that the build success/failure is visible in those services. Does anyone know?

It looks like there is a separate document about that, here. It basically requires writing a script that posts to the status API.