Not really. Crushing the Nazis' free speech doesn't do any harm at all to their ability to talk with one another, but it does insulate them from the wider community that might otherwise be able to talk sense into them. Also, it provides an environment where it's a lot harder to recover free speech for the leftists once things recover to a more stable civil society.
Every case is different of course, sometimes it is okay to censor for particular reasons, but in general my opinion is that reducing insulation between communities is better.