Baio himself probably pulled it because of a few inaccuracies. Where would the idea the Mezvinsky is related to Soros come from, besides sources that are banned on FR and a lot of other respectable sites?
It could be, but we have seen such a rash of companies censoring opinions with which they disagree, (have you been hearing about Google and Twitter lately?) Occam's razor implies it was done by Facebook staff.