If you use the token Fields.TokenName instead of the token itself then that indicates that the text will be replaced by whatever data is in that template field for the document. This allows you to update the field values manually at any time, without needing to change other locations where the same data is used. Since the data could change at any time, it always shows the token syntax until submitted.

If you want the document name to show the actual data, the token itself needs to be used, but if you need to make a correction, you may have to make that correction both in the field and anywhere else you use the token.