There is a sort of indirect way:
The converter Tag-Filename allows you to modify filenames by using tag information.
If you extend the mask to define the new filename by addressing an absolute path then files will actually moved from one directory to another (all files that are not handled by MP3tag stay where the are, though - which may be troublesome with external album pictures).
If you have several files that have identical tags then if would not be possible to rename them to a single file. Mp3tag would leave them as they are.
If you have (e.g.) a folder with the old music, then load this folder, e.g. m:\oldmusic.
Select all files.
Open the converter tag-filename and enter a mask that looks like this:
m:\newmusic\%artist%\%album%$num(%track%,3) _ %title%
This would attempt to move/rename all the files to m:\newmusic but will fail for all those files that have tags that would lead to filenames that are already there. These files would stay in m:\oldmusic.
So if you are sure that your tags are really well kept then this would be a first approach.
The disadvantage of the method relying on tags is that minute spelling differences will lead to new files although the contents is the same or equal tags will lead to the renaming error although one version is the radio edit and the other the live version...
In the end you will need several turns to get it right. The program Similarity is a good help but also requires a lot of manual work....
There have been several approaches documented inthis forum, some attempting to utilize the md5 checksum, others to get the tags right. But in the end, the effort to get one method foolproof method is almost as high as checking all the tracks manually....
No one has yet found th Philosopher's stone.