No, they cannot publish false information, because: 
 *It is illegal for a newspaper to publish false news like that. A newspaper has no right to publish false information like that because there are laws against that. Someone who publishes false news is very likely to be sued till bankruptcy and could end up in jail. 
 *The newspaper with the information is a reputable one (which means that it is known to publish only legitimate information). 
 *Moreover, if they published a fake news, Rainbow and Nickelodeon would sue the newspaper and they would lose a lot of money, and no one is stupid enough to do that. 
 *More than one reputable (which means they are known to publish only real news) have published announcements that Rainbow will produce a seventh season. 
 *If the information was false, Rainbow and Nickelodeon would have immediately said that it is false. However they have not done that. 

 The rules of Wikipedia clearly say that newspapers are reliable sources. If you don't believe me, then read it at WP:IRS#News_organizations and WP:CS#Newspaper_articles. You cannot prove that it is false and, as long as Rainbow and Nickelodeon don't themselves state otherwise, the information is assumed to be true and according to the rules the information has the right to be on the page so long as it has a reliable source, and a newspaper actually is a reliable source. More than 50% of Wikipedia's articles have newspapers as sources. That's how the real world works.