FB is not in fact banning any speech here. You can say what you want as long as you are speaking on your own behalf, using your true identity. What is problematic here is that people have created false identities and use them to influence public opinion. That is a clear ToS violation.

Quote: "It’s clear that whoever set up these accounts went to much greater lengths to obscure their true identities than the Russian-based Internet Research Agency (IRA) has in the past. "