Dropbox does not preserve file metadata during a variety of common operations like unsharing a folder. This includes destroying the date a file was created and the date a file was modified. Please preserve this file metadata for all Dropbox operations.
For example, if I "Unshare" a shared folder, Dropbox will change the file creation date of the original file on my local machine to the date it was unshared. In addition, Dropbox continuously changes the file modified date on files that have not actually been modified. Doing so destroys a users ability to search for files by these dates, sort files by these dates, and destroys the audit trail for files.
Dropbox's technical support team has stated (on multiple occasions in the support forums) that this is "expected behavior". However, the command is called "Unshare". There is nothing in the title of that command that indicates that executing the command will destroy file metadata in the process.
I suggest that you change the expected behavior of the Unshare operation to preserve the file-creation date of the original files during an Unshare operation. Doing so would follow the software-design practice known as "The Principle of Least Astonishment":
https://en.wikipedia.org/wiki/Principle_of_least_astonishment
https://wiki.c2.com/?PrincipleOfLeastAstonishment
At a minimum, you should inform users (via a dialog box) that "Unsharing" a folder will change the file-creation date (thus destroying the original file metadata) and give the users the option to preserve file metadata while executing the operation. As a general software-design practice, destructive operations should be explicit and allow the user to opt-out of destroying information if they choose.
Please feel free to reach out to me if you have any questions or would like any additional clarifications.
