kernel-default-base is built from a separate set of .spec and .changes files,
making use of the kernel-subpackage facilities.

This however means that the changelog of the original kernel packages
(kernel-default, -vanilla, etc.) does not end up in the changelog of
kernel-default-base. This is especially visible in updates, which only change
the binary content and the version number in an unobvious way. There is no
mention of any relevant fixed bugs (bsc#, CVE-).

It would be very useful to include the kernel changelog in the
kernel-default-base package. I don't think it can (or should) be interleaved
with the subpackage .changes file, but it could be included as file.

The target systems usually have excludedocs enabled though, so marking the file
as %doc means it won't get installed. That makes it more complex and
annoying...