Yes this is true. Google will rank web pages, based on the inbound links pointing to the page, even if Google hasn't crawled the page itself.

This happens regularly when a web page is blocked from crawling via Robots.txt file. Google still indexes and ranks the page, but Google has no idea what is on the page.

Want to keep a web page out of rankings? Allow Google to crawl it (by not restricting via robots.txt), but use a NoIndex meta tag or X-Robots-Tag HTTP header to indicate that the page should not appear in search results.