How big is the issue of no file size obfuscation with some encryption tools?

I have researched that some encryption tools like Cryptomator, have no file size obfuscation.

Source:

github.com/cryptomator/cryptomator

File size obfuscation

opened 08:05AM - 18 Jul 17 UTC

closed 08:08AM - 18 Jul 17 UTC

      pgassmann
    

Basic Info This is a - bug report. (privacy) - feature request. (randomi…ze file size) ## Description From reading the documentation on the security architecture it looks like the file size is not obfuscated. The file size is not exactly the original file size, but all the headers and metadata have fixed size. So it should be possible to calculate the exact original file size from only the encrypted file. Especially for bigger files this could be enough information to identify the file(s). E.g. a collection of a series/movies. A small randomly sized block could fix that. E.g add a block of 0% to 1% of filesize.

My question is: How big of a deal is this for privacy? Cryptomator protects the file name and content, but if someone stores media files, determining the exact file size, could enable someone else to identify the content. Because of for example a song.mp3 the unencrypted version is publicly available.