Word 2016 Page Setup dialog is missing Other pages section
We are seeing reports of the Page Setup tab is missing the Other Pages section on the dialog.
We have confirmed this issue, and a fix is being released. If you need this functionality immediately, it is available in the Office Insider channel and is expected to be released to the Current Channel shortly.
Update: The fix has been rolled out to the Current Channel, build 16.0.7167.2040
How to switch from Deferred Channel to Current Channel for the Office 365 suite