When I downloaded talloc-2.3.4 source, I tried to find what changed from the previous version. I looked at the NEWS file and it has not been updated in 15 years. If you are not going to update it, why do you continue to distribute it in the source tarball?
That said, we at linuxfromscratch like to tell our users what has changed since the previous version. Most developers include a NEWS file or equivalent with a summary of the significant changes listed.
Note that the git log is not very useful. It is far too verbose and includes many changes that are administrative in nature. Many of our users are not programmers and too much detail does not make the decision to the question 'Do I need thus update?' difficult. An entry like "Merged pull request 1234" is virtually meaningless.
A line or two saying why the changes in the new release were made or what behavior was fixed is much more useful.
The requested info does not have to be in the tarball, but changing the NEWS file to provide a URL where release notes are located would also work well.