1. Make any rename rule active to see changes in preview.
2. Select folder with files Ctrl+A (select all)
3. Hold Ctrl and click last file in the list to deselect.
After this one of the files near top of the list also deselects (although it appears to be elected) preview changes to show old filename as if its deselected.
You can click rename and see all files in selection except one (not the one you have not deselected) are renamed.