"To upgrade a GeoAnalytics server to the latest version, run the latest version of the installer. Configurations from the previous installation will be loaded (including data package services)."
There is no document so far stating that data package must be upgraded to match the server version. However it is recommended to upgrade to the later version of data package as it will provide latest data.
You can refer to upgrade section on the installation guide from the download site:
The activation part is the same as the new install.
4. Qlik Geo analytics extensions
To upgrade the extensions you have to remove the existing ones first otherwise the extension with the same name is detected.
You can keep all the GeoAnalytics virtualization there. But as the core for these extensions are change, you need to remove and re-create the GeoAnalytics virtualization for any fix or improvement in new extension.