No, you do not need to install the updated cMap. That said, it is highly recommended that it be kept up to date.
As for installing updates… if you have a recent version of cMap (4.0 or newer) and you have activated your support license on the Connections : Settings admin page under the Licenses tab, you’ll receive updates in the admin about updates to the template like and can update it like any other plugin.
Hope that helps. Let me know if you have any further questions.