When the patch 141583 is deployed, if the reference list markup is missing then the reference list will automatically show at the end of the page. 'MediaWiki:Cite error refs without references' will no longer be triggered and no error will show.
The manner in which the automatic reference list is displayed has some issues.
* No markup is inserted, thus follow-on editors will be confused as to why the reference list is showing. There will be a learning curve associated with this.
* No heading is added, resulting in a layout issue.
* The automatic reference list shows at the very end of the page, again a layout issue.
On the English Wikipedia (and perhaps others) the error currently places the page in a maintenance category so that concerned editors can repair it.
Without an error message or a category, there is no way to track this. Either repurpose 'MediaWiki:Cite error refs without references' or add a different MediaWiki page that is triggered when the automatic reference list is generated; it will the place the page in a hidden maintenance category. On the English Wikipedia, this is 'Category:Pages with missing references list'.