This allows us to ensure that things are working smoothly before releasing the feature to a wider audience. We often roll out features (and sometimes even fixes) over a period of time.But, some features listed in the release notes are only available if you have a Microsoft 365 subscription. Starting with the 16.17 release in September 2018, these release notes also apply to Office 2019 for Mac, which is a version of Office for Mac that’s available as a one-time purchase from a retail store or through a volume licensing agreement.