The chilling effect is entirely about the speech suppression. One of the side effects of speech suppression is that one no longer knows what people really think

The chilling effect is entirely about the speech suppression. One of the side effects of speech suppression is that one no longer knows what people really think, and there isn't good evidence that silencing someone changes their mind, which is the really important thing. There were vigorous efforts to silence the Nazis for example, and none of it mattered, because all speech control efforts target symptoms and not causes. About right-wing terrorism, pretty sure that's independent, as it has always been there.