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
with self.set_env_proxy():
                        package = fetch_file(self.module, spec)
                    envra = self.local_envra(package)
                    if envra is None:
                        self.module.fail_json(msg="Failed to get nevra information from RPM package: %s" % spec)
                    
                    if self.is_installed(repoq, envra):
                        pkgs['update'].append(spec)
                    else:
                        pkgs['install'].append(spec)
                    continue
                
                else:
                    if self.is_installed(repoq, spec):
                        pkgs['update'].append(spec)
                    else:
                        pkgs['install'].append(spec)
                pkglist = self.what_provides(repoq, spec)
                
                if not pkglist:
                    res['msg'] += "No package matching '%s' found available, installed or updated" % spec
                    res['results'].append("No package matching '%s' found available, installed or updated" % spec)
                    res['rc'] = 126  
                    self.module.fail_json(**res)
                nothing_to_do = True
                for pkg in pkglist:
                    if spec in pkgs['install'] and self.is_available(repoq, pkg):
                        nothing_to_do = False
                        break