I never thought they did it 'automatically'. My impression was that they always had to have found it via a link from another site, or that the site owner had to submit the site to Google. It isn't like Google is seeking out all registered domains and checking each one to see if a site suddenly appeared on it.

So if someone registers a new domain, puts a site on it, doesn't link to it from anywhere else, doesn't submit to to Google... and yet expects the site to be found by Google, that is just not a reasonable expectation.