if we are talking about an internal audit. Sure, doing a surprise audit is a bad thing! But what's sharing your checklist before the audit got to do with it?
Do you think the auditee gives a fig for what you've got on your checklist?:mg:
Do they understand what the words mean, what you're looking for etc? You have to stop doing audits like 3rd party/Registrar auditors and join the 21st century!!
Most internal auditors get trained and behave like 3rd party/registrar auditors. No wonder folks get defensive when an audit is done! When did anyone who's planning an audit, actually involve the management of the process? When did any auditor actually ask management what they want to see corrected or improved about their process(es)? Shouldn't the checklist be details of those problems, instead of some dumb questions, based on phrases of 'ISO' that no-one has ever read or understood
It has zero/nothing/zilch/nada to do with 'sharing' checklists. It's all about how effectively you schedule, plan and prepare for the audit. For example, how many audit managers/process owners schedule a whole year's worth of audits on some kind of calendar? It's not required to do that, but most 3rd party auditors want to see it done that way!

So the organization's management get little/no benefit from audits - try asking them (of course they won't tell you straight, but if you didn't maintain an 'ISO' registration, just see if they'd continue to pay for/support internal audits)
Of course, 3rd party auditors will always do what they do, because they don't learn from their experiences. They've (essentially) been doing audits the same way since they started over 15 years ago