A Content Wizard revision is outdated if it is based on a Data Backbone revision that does not exist anymore, because it has been changed. In other words, the outdated [in development] Content Wizard revision cannot be recreated exactly as it is in the current state. Saving the Content Wizard will make it up to date again, reflecting the changes to the Data Backbone revision(s).
Deleting, renaming or moving elements of the types Fieldset Array, Data Structure, or Data Structure Array in the Data Definition component of a Data Backbone will outdate the Content Wizards based on this Data Backbone. Additions to a Data Definition component will not result in outdated Content Wizards. Any changes to the Data Retrieval component of the Data Backbone will also not result in outdated Content Wizards.
When an outdated Content Wizard is unlocked the outdated [in development] revision is changed into a revision proper, but not made the [current] revision.