I might sound nitpicky but the language is important. “Might” or “may be” or “slower than usual” are vague and don’t offer the sender all that much information about when you’re really going to respond to them. Worse, they do a horrible job of protecting the time of the email receiver who, as the responder notes, is not in the office! Such a responder implies that, not only will the vacationer reply to the email, but they may not even miss a beat. They may be slow to respond, but they also might not.
The boss’s thinking was that people who did drivebys looking for you would then email you, see your OOO, and then be able to call you to talk about whatever they were driving by for. No one liked putting their personal contact info so we never worked from home (pre-COVID and pre-VOIP implementation) or told people to IM us and we’d call them.

I’ve mentioned this before, but I’m really tired of the ones that are basically “I’m in a meeting for an hour and I’ll check my messages when I return.”
I set mine for long meetings (half a day or a whole day) or if I’m traveling. I do have clients who email about time sensitive issues and it’s better for everyone if they know I might not see their message for a few hours.