This is pretty standard practice, and follows the Fedora packaging guidelines.
> The intent is to give the user a hint as to what changed in a package update without overwhelming them with the technical details. They must never simply contain an entire copy of the source CHANGELOG entries.
https://docs.fedoraproject.org/en-US/packaging-guidelines/#changelogs
It sounds like what you're looking for is the upstream changelog.
https://gitlab.freedesktop.org/pipewire/pipewire/-/blob/1.6.4/NEWS
> The intent is to give the user a hint as to what changed in a package update without overwhelming them with the technical details. They must never simply contain an entire copy of the source CHANGELOG entries.
https://docs.fedoraproject.org/en-US/packaging-guidelines/#changelogs
It sounds like what you're looking for is the upstream changelog.
https://gitlab.freedesktop.org/pipewire/pipewire/-/blob/1.6.4/NEWS