You mean "harmful conspiracy theories" such as previous suggestions that COVID might have accidentally come from a lab accident? or that the vaccines didn't work as wonderfully as first advertised, or that they may just cause harm to some people? How about others that also later proved to have some truth to them. All of these things would have been perfect candidates for using your supposedly moderate "harm reducing" stance on free speech to snuff out worthy debate even if some of it is colored with tones of irrational conspiracy thinking.
And that is exactly why free speech moderation is so dangerously stupid. It allows reasonable sounding people to crush attacks on reasonable sounding ideas, right up until both these reasonable ideas and the people supporting them become unreasonably authoritarian, and attack even wider ranges of open expression.