Yup. If you look at the end of the 'changes' link[1] you'll see individual bugzilla links for issues (or PRs as they call them) that were resolved in a given point release.

[1] https://gcc.gnu.org/gcc-9/changes.html

The ChangeLog file is in the source code distribution. But the point releases mainly have a large number of bug fixes, there are no new features.