It is true. I made a ridiculous looking wikipedia article back in 2006 while making a scavenger hunt for my girlfriend. For more than six years that article has sat there, even though it references fake people, fake companies and fake quotes. It has even been cleaned up a little by others over the years.
The worst it got is a 'this article may contain original research' tag. I'm sure if it had widespread exposure someone would realize it is completely fake. But articles on wikipedia just don't get exposure. They sit there until someone looks them up. And that person is rarely an expert.