Temporary Report Communications

It would be useful to have the ability in the Power BI Service to add a temporary message / overlay to a certain report to display important messages.

For example, we have a dashboard which contains a number of different visuals based on a source system in our NHS Trust. The system is going to have 4 hours of planned downtime later in February to carry out an upgrade, which will be during core working hours (between 6am and 10am). Ideally we'd like to add some form of communication to the report to explain why the visuals are blank or have broken. At the moment this isn't possible, so we'll just have to add a temporary text box banner to the report in desktop and publish this temporarily during the upgrade period.