There may be no technical limitation to not setting dnd all the time but it effectively means you either have this app for some reason other than the main pitch or you're forced under this apps surveillance/interruption mode by the org. In either case the thing solved in this scenario is not reducing meeting interruptions for the user.
I think I lean with the others that the problem this app aims to solve is not really a technical problem. That said it doesn't mean there won't be lots of businesses interested in the app.
In the workplace, being DND all the time is not a thing that can realistically be done. It's not socially acceptable and I'm quite sure that your boss will sooner or later demand that you stop doing it.
