The problem with that is people just don’t look at your signature. Whereas they are reasonably likely to notice the OOO message in the email subject header.
Hah! Maternity/parental leave is often 1 year here, so there is zero expectation you will read or “catch up” afterwards. We keep our email addresses during where I work (Canadian government), so it’s standard to put an OOO that just says “on parental leave. Please contact X instead” with no reference to actually reviewing any of those emails, and often not even a projected date of return since people often flex their return date or take extra time, or just return to a different position entirely (out of choice).

In this image, you’re letting people know you’re OOO with a “Missing” notice on a milk carton. Genius. Just be careful — this sort of autoresponder is best for internal emails, not for autoresponders that get sent to prospects and clients.
When it comes to professionalism, keeping things short and to the point is a good idea. What’s more, if you write a short auto-reply email, you don’t spend too much of the limited time you have left before your vacation.