Considering that this site is for questions about Tor, I'd say a question about what events led to Freedom Hosting's disappearance might be considered on-topic, considering that you did mention that Freedom Hosting was a part of the Tor network.
However, the issue I see isn't really whether or not it's on-topic but instead that it's a question about a current event or a specific moment in time. The best Stack Exchange questions are about a real, actual problem you're facing; instead, this question may very well lead to speculation and debate. This doesn't by itself make it a bad question, it just makes it tough to fit with the Stack Exchange Q&A model.
It's best to not think of this site as a discussion site or a replacement for other forums and resources out there on Tor. This isn't a place to discuss news, current events, or announcements; instead, look at this site as a place to find expert answers to problems you face.
Hope this helps! :)