The usefulness of the DLSIP categorisation is predicated on packages appearing in The Module List. I think the current statistics are something like less than one in three distributions. The more recent the first release of the dist., the more likely the author has never even heard about it, nor knows what to do about it. META.yml is shaping up as the way to store metadata about a distribution.
• another intruder with the mooring in the heart of the Perl
It's not that the distributions appear in the Module List, which is unmaintained and dead, but that people have registered their namespaces in PAUSE so they can more PAUSE maintenance features and can set some meta-data in PAUSE. Most of the meta-data should probably be in the distribution itself, but most of them don't have that.
THE DLSIP categorization is still useful though, because it doesn't matter how many other modules use it for it to matter for one distribution. The categorization itself is not useful because of its source, and the same categorization would be useful in META.yml. Now that META.yml 1.4 is the current version, maybe we could add more categorization stuff to the spec for the next version. :)