Pop-Up windows / message if a user opens a workspace / report / dashboard

Would it be possible to add / present on the levels of workspace / dashboard / report a pop-up window / message to end-users? Idea is based on a respective SAP functionaliity if you log into a system, that the admin can present a user message (e.g. about planned downtime). In the sceanrio with Power BI such message might include information about new features / data content / etc. So really meant as temporarily (not misued as annex).
So it would also be cool while creating such a message to specify the timeframe when it should be presented to the end-users (esp. an END-Date).