You'll receive a notification on your desktop about the new version just like you do for other releases. What's more, the August release (version 15.25) will arrive just like any other update to the apps. This new update makes Word, Excel, PowerPoint, Outlook, and OneNote 64-bit for anyone running Retail, Office 365 Consumer, Office 365 Commercial, and Volume License installations of the software. With this latest update, Office 2016 for Mac is making the permanent switch to 64-bit support which Microsoft says will boost performance and allow for new features. Apple's desktop operating system has been 64-bit for a while now, but Windows still allows users to to choose between 32- and 64-bit versions. The update is rolling out to those who are running Microsoft's productivity suite on OS X. Microsoft announced in April that it would make the transition from 32-bit to 64-bit for Office 2016 for Mac.
