I can’t see anything that says it’s all about free speech. I can see this though. “Freedom of expression means little if voices are silenced because people are afraid to speak up. We do not tolerate behavior that harasses, intimidates, or uses fear to silence another person’s voice. If you see something on Twitter that violates these rules, please report it to us.“

https://help.twitter.com/en/rules-and-policies/hateful-condu...