Necessity is the mother of invention. Isn’t it? We had a scheduled downtime earlier for CRM and the downtime notification email was sent earlier. The user I was working with wasn't aware of it. The user was super busy responding to CRM cases and did not find time to check the email. The downtime started. Finally the user was totally caught unawares when the browser eventually hit the server error while working with CRM. The panicked user lost the email drafted for the case. We may not be able to blame users for not checking their email beforehand.
How about a PCF enabled Announcement control which shows a configurable message like an announcement upfront that scrolls across the CRM page on top - which will catch the attention of the user while they work on. This will remove their dependency to check emails and help to be more productive by planning their work ahead of such downtime.