I see stuff like this in source controlled repos all the time! The argument is that, even if it's in the git history, it'll get lost/forgotten about in case it's ever needed again.

In some(!) cases it totally makes sense to provide a hint for the person who might read the source code and wonder why there is a certain 'void' recognisable in the code, because it has been designed around another piece of code or data that is no longer there. Better to keep a short comment in the source file for readers to stumble over, and then via blame it's easy to read up on the whole history in version control.