Naturally, you want to help your clients and other business associates to contact you in the best and easiest way possible. For that to happen, you should provide out of office messages when you are not available.
There’s a department at my workplace where this is common practice too. My old department worked with clients in similar ways, and I was half expecting we’d also be required to do it, but luckily that never happened. Further proof that, at this (generally progressive, flexible-working) company, your actual work-life balance heavily depends who manages you.

Yes! I remember reading here the phrase: the default mode of clever is asshole. Meaning when trying to be clever backfires, you end up just looking like an asshole. I’ve given up the need to get laughs at my clever sense of humor while at work. I really hope that out of office message is for internal emails only, because the risk of this landing badly is too high.
But let’s talk out-of-office messages: overshares, excessive detail, the ones that self-aggrandize (I once had a coworker whose auto-replies often said he’d be in late because he “pulled an all-nighter” on various work projects, etc.), the ones that never get turned off, people who don’t use them at all, and other pet peeves.