Computer Configuration > Administrative Templates > Microsoft Edge
Both
HKLM\Software\Policies\Microsoft\Edge
This setting controls the in-browser assistance notifications which are intended to help users get the most out of Microsoft Edge. This is done by recommending features and by helping them use browser features. These notifications take the form of dialog boxes, flyouts, coach marks and banners in the browser. An example of an assistance notification would be when a user has many tabs opened in the browser. In this instance Microsoft Edge may prompt the user to try out the vertical tabs feature which is designed to give better browser tab management. Disabling this policy will stop this message from appearing again even if the user has too many tabs open. Any features that have been disabled by a management policy are not suggested to users. If you enable or don't configure this setting, users will receive recommendations or notifications from Microsoft Edge. If you disable this setting, users will not receive any recommendations or notifications from Microsoft Edge