Preventing spread of misinformation is good, but preventing the spread of "information" in a context where people are already sensitized could be worse. It depends on whether people will assume censorship/blackout means something negative, and whether the communications tool is actually needed to organize the responsive violence. It depends on the specific culture/society.

Its worth it when its gonna prevent deaths because of propaganda. In India, its a main source of misinformation and it has caused numerous deaths. For example in last month's deadly Pulwama attack which killed 40+ soldiers in an attack by a terrorist in Kashmir, Right wing Hindu extremist groups started spreading misinformation saying that "Kashmiris all over the country are celebrating the death of soldiers." They shared old photos of random kashmiris being happy. This let to multiple attacks on the kashmiris all over the country. This is exactly what needs to be prevented from ever happening again. I'm willing to give away social media for a few days if its gonna save some fellow countrymen's lives no matter if they're innocent or not. Please understand the context.

trouble is that social network helps misinformation spreading at a faster rate than "good" information.

Initial misinformation, is usually quite widespread before any correction is issued, and even then correction usually get less spread ( mostly because people who have been spreading misinformation would not admit that they are wrong ).

Also blocking, muting and bubble effect contribute to wrong information staying in the same sphere.