I've recently discovered that any WhatsApp account can only receive a certain amount of marketing templates from ANY business within a 24 hour period. If you send a marketing template to a user that has reached their limit then it simply doesn't send. Automations are registering it as delivered though whilst in conversations it says unsuccessful.
It would be beyond helpful to have an action in workflows that registers whether a WhatsApp message has been delivered or not. In the same way we can use "Valid WhatsApp" to see which numbers have a WhatsApp account, a message delivered step could allow us to notify the user if someone hasn't received the message or build an automation loop that will not move on until the message was delivered successfully.