If I had a guess to venture, this late in the life-cycle of the product, I would suspect that this has something to do with the approaching 'sunset' of QuickBooks 2017 desktop products on May 31, 2020.
In other words, everything within this update is behind the scenes and they are not telling us, at least not in the official 'release notes' what it is. This update contains no visible changes to your product.
You can manually download the update from the Official Intuit QuickBooks Downloads and Updates Webpage (product/version specific). If you have automatic updates turned on, QuickBooks will download the updates for you and prompt you to install it. Be aware that each new update also includes all the changes from earlier updates.
The changes, improvements and fixes elaborated below were included in this release for QuickBooks Pro 2016, QuickBooks Premier 2016, QuickBooks Accountant 2016 and QuickBooks Enterprise v16.0. Intuit has begun rolling out Release 16 (R16) to the QuickBooks Desktop Product line.
