Cumulative Update 1 for Exchange 2016 has been out since 03/15 but I didn’t get a chance to write about it. Below you will find some step how to roll it out in your environment. Of course it has a number of fixes and that’s the reason you need to update you server. The server patching process is different on a single exchange server 2016 and in a environment where you have more than one server and running DAG and CAS behind the load balancer. For a HA environment , you will need to plan accordingly.
This is one of the example when you run this cmdlet on Exchange 2016 prior to CU 1
Below is the screen capture of Exchange 2016 RTM version (before CU 1)
Here is the installation process


Here is the Server build of Exchange 2016 CU 1 with a new schema
List of issues fixed by CU 1
Here is the list of all issues fixed in this Cumulative Update CU 1
Updated OWA S/MIME control
New distribution package for Exchange Server 2016 update
Change to Mailbox Anchoring for Remote PowerShell
Additional languages for Outlook on the Web
.Net 4.6.1 Support
Slow installations on Windows Server 2012 R2
Support for Standalone Hybrid Configuration Wizard in Exchange Server 2010
.Net 4.6.1 Support
Make sure you are not running this version of DotNet Framework. This version is nut supported yet.
For the latest information on Exchange Server and product announcements please see What’s New in Exchange Server 2016 and Exchange Server 2016 Release Notes. You can also find updated information on Exchange Server 2013 in What’s New in Exchange Server 2013, Release Notes and product documentation available on TechNet.
Now if you run Test-ExchangeSearch , you will get this cmdlet working
Now you have successfully installed the CU 1
Cheers:)