If you have a machine(s) that are currently running CCA and for any reason need/want to downgrade this. Your machines will report a 100% status but still be running the previously assigned version of the CCA.
Attempting a 'Poll Now' or an 'Install Deployment Agent' bodes no change in this behaviour also.
Your environment/deployment group will still continue to work as expected and is expected behaviour.
The Deployment Agent (CCA) has never been supported for downgrades and will not downgrade if the installed version is higher than the one listed in packages for the deployment group.
Solution / Workaround
Machines will need to have the Deployment Agent uninstalled manually or by unregistered and deleting the machine from the deployment group, however please bear in mind that unregistering and deleting a machine from a deployment group would remove all agents.