Deleting Notification/Trigger is not removing them from the DB

If I create a notification entity in composer, and a trigger, it will put information about this in 2 tables in the DB (notificationcontent_model, notificationdefinition_model). When I delete a trigger, it is not deleting this row from the table. Because of this, I cannot create a new trigger with the same name on the same notification entity. For now, I have been deleting this row in the DB table in order to ensure this name is available for use again. I also noticed the same thing happens if you delete the entire notification entity. None of its data are removed from the tables in the DB.

Is this a bug? Are there any side effects to removing these rows from the table in the DB when a trigger is deleted?