Auto enrollment failure - Is retroactive opt out permitted?

[Clare]

The 401(k) plan has auto enrollment. Apparently a few years ago, three participants were not auto enrolled and it was discovered on audit. HR spoke with these employees and they all indicated they would have opted out from the start if they had been provided with an opt out form. If we have them sign a document indicating they would have opted out, will that save us from having to make corrective contributions on their behalf? Of course that would save us money and make our lives much easier, but it somehow doesn't seem quite right to me. While the employees are willing to execute such a document, I could see the IRS arguing that employees could be pressured into signing such types of documents to please their employers etc. 

Any input would be appreciated. 

[PensionPro]

47 minutes ago, Clare said:

If we have them sign a document indicating they would have opted out, will that save us from having to make corrective contributions on their behalf?

No.

[K2]

Sorry. You’re on the hook for deferrals and match