Gulag is a poor analogy. Freenode can't imprison people or force them to stay on their service. Nor can it control the spread of information and opinions. Lee might own Freenode, but he doesn't own the front page of Hacker News.
In terms of effectiveness, this is perhaps more analogous to the boss screaming, "You can't quit, because I just fired you!" It doesn't keep anyone from leaving, but it does create unnecessary drama and make them look bad.
On the other hand, if Freenode had done nothing, it wouldn't have stopped some communities from leaving, but the flow might have abated all by itself. Like my mom used to say, "It won't heal if you don't stop picking at it."
In terms of effectiveness, this is perhaps more analogous to the boss screaming, "You can't quit, because I just fired you!" It doesn't keep anyone from leaving, but it does create unnecessary drama and make them look bad.
On the other hand, if Freenode had done nothing, it wouldn't have stopped some communities from leaving, but the flow might have abated all by itself. Like my mom used to say, "It won't heal if you don't stop picking at it."