User Configuration > Administrative Templates > Microsoft Outlook 2016 > Outlook Options > Other
User
HKCU\software\policies\microsoft\office\16.0\outlook\options\general
This policy setting determines whether the Preview Place feature is allowed. If you enable this policy setting, you will block the Preview Place feature from being available to your users and they will no longer be able to preview and provide feedback on upcoming changes in Outlook. If you disable or don’t configure this policy setting, the Preview Place feature will be available to your users. Note: This policy setting only applies to subscription versions of Office, such as Microsoft 365 Apps for enterprise.