I think it would be good if Tag-Filename (like all potentially time-consuming operations) showed some indication of activity, progress and completion e.g. popup-dialog with progress bar and/or status bar messges. I just did a 6000-file conversion taking over 1 min and there was none. The status bar remained showing the the completion message of the previous operation, until T-F completed, where upon it changed to Ready.
I've added the progress dialog for Tag - Filename with the current Development Build v2.40a.
It appears that the message that is displayed after the operation has been finished is not really meaningful.
I'll fix that to the next release.
Fixed with Development Build v2.40b.