Hey @Bandit-K, thanks for posting your question!
With shared links, there's currently no way to show the 'date modified' of a folder, but you can see it for a file.
A workaround in this case would be for you to create a folder named 'updated folders' for example, which would include the ones you've modified.
Or you could rename the folders you update to 'Folder name (updated)' to indicate that they've been updated.
I hope this helps a bit, but let me know if you have any questions.