When a WORD (or EXCEL) document is added to the GVO that contains 'track changes' or 'comments' these are NOT visible in the preview of the document.
If you wish to have the 'Track Changes' and 'Comments' visible in the preview then save your WORD (or EXCEL) document in PDF format on your computer and add that PDF file to the GVO - these will then be visible - see example below.
Note: You may need to check the 'save as' settings in WORD or EXCEL to have the comments showing. In the case of EXCEL you may need to 'Print to PDF' (with settings adjusted) to make the comments visible.
Note: On a 'Page' or a 'Policy' you can add the WORD document and also the PDF version (with track changes) - when the Policy is Final/Published both files would be visible and so the final, no track changes version must be there and nothing else.