In the past, some SELinux policy packages provided SELinux modules whose
name didn't reflect the package name. For instance, selinux-gnupg provided
the "gpg" SELinux module.
A year or so ago, our SELinux module packages got a standard naming
convention so that selinux-<module> provides the <module> SELinux module.
Or, in the example above, "selinux-gpg" provides "gpg".
The ebuilds that had a "wrong" name got updated to DEPEND on the new package
(so they act as some sort of wrapper) so that we didn't have to introduce
package renaming. I've now also removed all dependencies on these wrapper
packages and will remove them from the tree in about 30 days.