Here's the thing, prior to the Internet, to these social media sites, how many people would have seen this story? How many would have believed it? It would have been in magazines in the checkout stand, since it could not be validated by real media. At most, it may have ran on Fox News. Why? Because it isn't more than a tabloid story. It doesn't deserve legitimacy without some way to check its authenticity. Would you be upset that other media outlets weren't covering it, despite it being in a paper that is classified as a tabloid?
en.wikipedia.org
These social media sites are private businesses. They are not creating news. But they have a right to block anything, any content that does not fit their TOS, their expectations. Notice how no one complains when they remove pictures of naked people from feeds. No one complains that that is censoring content (it is, just the same as removing news stories).