For businesses that prefer more time to integrate, train, and support new builds, Microsoft Office releases updates on its Deferred Channel. New features only come to the Deferred Channel three times a year: February, June, and October. This month, Office 365 accumulated a long list of features and security updates. For a full list of the new features, visit Office 365 client update channel releases.
More interesting to note, administrators and developers will notice that the Deferred Channel version numbers will be syncing easier with Windows 10's. The year and month numerals will determine the version number with a build number afterward to distinguish it. For example, May 2016 would be called version 1605.
The May 2016 Office 365 build will be made available on the Deferred Channel in October, and so make sure to begin testing as soon as possible.