No, Special:Deadendpages is a list of pages which
contain no outgoing
links, i.e. are "dead ends" - Special:Lonelypages is a list of pages
with no incoming links.
That's certainly how it should be, but it doesn't seem to be how it
is. Take a look at
http://www.thecatholicwiki.com/wiki/Special:Deadendpages, there are
plenty of pages on that list with links in them, and it's not just a
caching issue, either - the links have been there since the articles
were created.