the patches may be obsolete but not irrelevant - i believe they will only be tagged as irrelevant if the vendor removes the patch from their site.
the old versions are likely there because they are associated w/ bulletins. even though there are new patches/bulletins, you may want to only patch to a certain bulletin instead of the latest.
i don't think you can remove the 'old' bulletins and patches w/o having them re-added on the next CUJ.
is this causing a problem?