The government shouldn't be doing that. Also, it's important to break down what is meant by "the government" here -- it was the FBI attempting to suppress a news story which later turned out to be true about the son of a candidate for president. That sort of thing should not happen.
Secondly, this kind of moderation is counterproductive. It gives all the conspiracy theorists a true conspiracy to point to -- they really are being suppressed by "the man" or "the Feds" or whatever. Also, no matter how much stuff gets moderated, the left will never be happy.
End result: everyone is mad at Twitter, nobody trusts anything, conspiracy theorists get to make true claims about suppression, and more people are attracted to misinformation because it was suppressed -- e.g. "the government doesn't want you to know this!" or "see what the government is trying to hide from you!"