Hi Lisa thanks for posting in the Lucid community! While there is not a way to download the final version of your document that also includes all previous versions or a record of changes you can export previous versions of your document as a PDF. To do so open the Revision History for your document select the version you'd like to export and choose New from Version. 

This will create a new document based on that version which you can then export normally as a PDF (or any of the other supported file types). I hope this allows you to understand and share the changes to your document with your collaborators! If you'd like to see the inclusion of Revision History in a downloaded Lucidchart document would you mind adding your thoughts and more details about your use case to this feature request form? Ideas submitted here are passed along to our development team for their consideration when prioritizing improvements to the product. Thanks for your request and apologies for any inconvenience! Let me know if you have any additional questions.