Yeah, announcing you were going to delete emails unread and expecting the sender to resend when you return would NEVER fly in my office. I’d get executive complaints about that, especially if it went to a client or outside party – if a client can’t reach you, they will reach out to someone else who may not work at your organization and you lose business. I feel like this delete-it-all philosophy would only work for an entirely internal role where timelines are more relaxed, and even then, I feel it’s a bit unprofessional to foist your own catch-up work onto others, especially if they’ve been backfilling for you while you were OOO.
Under the customization option, you can configure the pre-chat form to create personalized offline messages. You can clearly mention the business hours and ask customers to fill up the form with the relevant sales or support query. Inform them that your support representative will be connecting with them at the earliest to sort out the issue.

I saw a version of this on IG that was an old school (paper) OOO from an associate pastor. It has a line like “if this is an emergency and you must speak to someone, Jesus is always available on the mainline.” Too funny.
Q. Who should notify contractors, vendors and other individuals who work with various University departments that their services may not be needed during winter break?