I once had a coworker who attempted to put up an OOO for all of busy season that basically said “I’m busy with urgent deadlines, so please expect a delay in my response.” I think she was asked to take it down.
I typically say “thanks for your message, I’m out until blah date, with periodic access to email” or no access depending. I list contacts who are willing to pitch in if necessary, and list the day AFTER my return that I’ll be able to address messages.

And describing their boss as elusive….taken in context with the rest of the message…seems a bit of an attempt to say, “I run this ship solo so good luck with getting them to “help”, lol”
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.