Does that make it okay? There are many ways to have it learn the process dies without needing to signal the process.

Yes, let's invent some system for Explorer to query and maintain the notification area icons and for the apps to report their list of the notification icons. Some KPI pusher would be vewy-vewy glad.

By the way, if the app wouldn't respond in time, what should happen with the icon? What would happen if Explorer removes the icon but the app which still thinks it has - would update it?