How can I exclude auto-open contacts from future database cleanups?

Summary:

Auto-open security settings masking engaged contacts

Content (please ensure you mask any confidential information):

We recently cleaned up our database using a range of filters to identify unengaged contacts over past 18mths. It appears that contacts with auto-open security were included in 'Not Opened Any Emails' and 'Not Clicked Any Emails' filters and were deleted from our database. I need a way to identify these auto-open contacts in the 'delete' segment but I'm unable to find a filter or Dashboard / Insight report that I can use to exclude them.

Version (include the version you are using, if applicable):

POD 7 - 25C