Nothing worse than starting iTerm and typing half a command when suddenly this thing interrupts you.
DND is not properly/reliably detectable for 3rd parties. Support for Notification Center is not well designed for a framework to control and works as an auxiliary/supplemental (not primary) functionality for 3rd parties, so apps themselves would have to opt into using it along with adding a lightweight UI indicator which may need to be tailored to the app in question.
Further support is available for apps to support more gentle reminders -- https://sparkle-project.org/documentation/gentle-reminders/ which is a mechanism that iTerm developer wanted but developer has other priorities.
Users can opt into automatically downloading/installing updates too which may minimize prompts