Pipeline variables are not assigned/initiated correctly in the job variables

Summary

When pipeline's variable is interpolated from other input variables, the job level variable doesn't interpret the pipeline's interpolation correctly

Steps to reproduce

variables:
  PROJECT_NAME: project-name
  PROJECT_VERSION: prjectVersion
  PROJECT_VARIANT: project-variant
  BRANCH_RELEASE_NAME: ${PROJECT_NAME}-${PROJECT_VERSION}-${CI_COMMIT_REF_SLUG}
  MASTER_RELEASE_NAME: ${PROJECT_NAME}-${PROJECT_VERSION}-${PROJECT_VARIANT}

job:
  variables:
    RELEASE_NAME: ${BRANCH_RELEASE_NAME}
  script:
    - echo "The release name is ${RELEASE_NAME}, but should be ${BRANCH_RELEASE_NAME}

The output in the console: The release name is ${PROJECT_NAME}-${PROJECT_VERSION}-${CI_COMMIT_REF_SLUG}, but should be project-name-projectVersion-branch-name