As you aware that Microsoft Exchange 2016 now adheres to a scheduled delivery model. In this model, cumulative updates are released quarterly.
Now you can download the Cumulative Update 3 for Exchange Server 2016. It resolves issues that were found/reported to us in Exchange Server 2016. So this update rollup is highly recommended for all Exchange Server 2016 customers. Here is the related announcement that we made last week
Note: Exchange 2016 cumulative updates include all the changes from previous updates and are full builds of the product. You don’t have to install the previous cumulative updates to get the latest features.