I have K9U, and both AR '60s Drums Vintage and AR '60s Drummer were installed and authorized by default. Drummer does look like a major upgrade to Drums, but both use the same kit photo. Drums had a single instrument, while Drummer added 3 additional instruments. I've been using AD2, and haven't tried either of the AR instruments other than to play them a bit while checking for this post.
I suspect that Drums is still part of the distro package to retain compatibility with older projects that used Drums. The interface might be cool, but why would you use Drums instead of Drummer on a new project? Do they generate different sounds? Was the kit resampled for Drummer, or is the one instrument that's common the same (drum map and samples)?