I am using the yum module to lock the release version for a RHEL 7.6 machine to 7.7 version. However the yum --releasever option does not set the release version to 7.7. I am using Ansible 2.7.10 version.
Here is the discussion regarding the issue: 
https://access.redhat.com/discussions/4774501

ISSUE TYPE
Bug Report

COMPONENT NAME
yum --releasever

ANSIBLE VERSION
2.7.10 

STEPS TO REPRODUCE
name: installing updated packages
yum:
name: '*'
state: latest
releasever: '7.7'

ACTUAL RESULTS
Play runs successfully however it does not update the release version of the server
- I(Plugin) name to disable for the install/update operation.
        The disabled plugins will not persist beyond the transaction.
    version_added: "2.5"
  releasever:
    description:
      - Specifies an alternative release from which all packages will be
        installed.
    version_added: "2.7"
  autoremove:
    description:
      - If C(yes), removes all "leaf" packages from the system that were originally
        installed as dependencies of user-installed packages but which are no longer
        required by any such package. Should be used alone or when state is I(absent)
      - "NOTE: This feature requires yum >= 3.4.3 (RHEL/CentOS 7+)"
    type: bool
    default: "no"
    version_added: "2.7"
  disable_excludes:
    description:
      - Disable the excludes defined in YUM config files.
      - If set to C(all), disables all excludes.
      - If set to C(main), disable excludes defined in [main] in yum.conf.
      - If set to C(repoid), disable excludes defined for given repo id.
    version_added: "2.7"
  download_only:
    description:
      - Only download the packages, do not install them.
    default: "no"
    type: bool
    version_added: "2.7"