If your request is urgent, there’s no use sitting idly in my inbox. So please send your request to [Contact Name] at [contact email]. Whether you prefer to stick with something simple or have a little fun with your holiday out-of-office message, it’s important that you always make sure to at least include the basics: your return date and an alternative contact people can reach out to for urgent matters.
It’s really only meant as a courtesy but if your culture is different I can see where it’s eye-roll y.

Yes, I phoned a dentist office late in the day for a reinfected root canal problem and got a cutsy “humphrey bogart” fake reply on their voicemail — I thought it was extremely inappropriate for a business office to use something like this. It was hard to find it funny, especially because while calling me “sweetheart” and all that, the message didn’t actually tell me when they might return my call (later that day? Next day? Next week? Never?) nor did they offer any options for emergency contact with another dentist.
Sure, Kopelman is truthful about the fact that he's on vacation, but he also lets the recipient know that he or she would be interrupting important family time if the first option is chosen. It states a point simply and uses humor to avoid making it sound like he wants the reader to feel guilty.