User Configuration > Administrative Templates > Microsoft Excel 2016 > Excel Options > Advanced
User
HKCU\software\policies\microsoft\office\16.0\excel\options
This policy setting controls the "Automatically Flash Fill" option found under File tab | Options | Advanced | Editing Options. If you enable or do not configure this policy setting, Excel will enable automatic Flash Fill. This is the default behavior. If you disable this policy setting, Excel will turn off the Automatic Flash Fill feature.