This is something we’ve wanted for a while. Apple has made huge improvements with its notifications, but there is still a lot of work to be done. For example, Siri Shortcuts/Suggestions for DND (Do Not Disturb) would be welcome. This could include a pop-up when arriving at the movie theater that asks if you want to use DND or the ability to customize what notifications come through when using different apps (such as playing a game). Setting a systemwide status is one way to achieve this.
For example, right now iOS has a Bedtime setting that dims the display and mutes notifications; but when you wake up, the weather and other information about your day is displayed. Apple could apply other statuses such as working, gaming, on vacation, and more that could be customized to your liking. These statuses could affect how your phone sends notifications and could even be helpful in iMessage.
Currently, iMessage can send an automated message while you’re driving; it would be pretty cool if it could send other messages when using a particular status or even show your current status to approved contacts.