Within ConfigMgr Current Branch (1602) the production client isn't updated by default anymore. After installation (and/or upgrade) both a ConfigMgr Client Package and ConfigMgr Client Piloting Package are created. This is different in earlier versions, where the production client was upgraded immediately. Benefit of this is to test the client first, before enroll it to all company devices.
Both a ConfigMgr Manager Client Package and ConfigMgr Manager Client Piloting Package are available now.
During upgrade a pre-production collection must be created. Just add a few systems in it for testing purpose, and you will be fine.
Within a deployment task sequence this can be tested to. Just deploy a system with the new pre-production client, and check if it's installing fine. Just choose "Use pre-production client package when available" and browse to the ConfigMgr Client Piloting Package.
When successful go to Cloud Services > Updates and Servicing > and check Client Update options. Check "I am ready to make pre-production client version available to production" to update the Configuration Manager Client Package. The ccmsetup.exe in the ConfigMgr client folder will be upgraded now. Yeah!
Just great to have more control on the client version now!