I’m not sure. Maybe there should be an “un-notification process” to ensure the notifications are removed from queue when the topics are moved away from a normal category. That may sound complicated, and certainly it is, but it’s very surprising to see muted tags popping up in this case. Maybe adding a delay before notification would have prevented this instance…
In any case, you’re right, this can happen to other people and should be easy to find. Maybe the people working on notifications could have a look and decide how to handle this situation. A feature topic maybe?