The attitude that there should be punishment or other some other serious consequence for the expression of opinions one is presumably not supposed to have indicates the presence of the authoritarian personality.

Take, for example, the belief that transwomen are women. This belief rests on the redescription of gender as a social construct, an internally sensed identity, or both (although holding both is a contradictory position). I have examined both assumptions (you will find those examinations on Freedom and Reason) and found the first routinely misdescribed and the second nonfalsifiable and therefore unscientific.
Of course, people are (or should be) free to believe that transwomen are women, but when this belief is imposed on others, and by imposed I mean some coercive means applied, a situation of tyranny is manifest. Tyranny is not diminished by claiming those subject to it are bigots as popularly understood (e.g., “transphobes”), since the charge issues from the side claiming to have the truth. It’s a substitute for substance.
For there is another side, and that is the belief that gender is a synonym for sex and that gender is binary and immutable. This is the majority position. To be sure, the majority can be mistaken. In this case, the majority is not mistaken because the science is as settled as science can be on the particular question; the belief is justified and therefore constitutes knowledge. But supposing it were not, and it wouldn’t matter for the right to express either side if it were (after all, people are free to believe in God and souls), the fact remains that there are two (or more) sides, and in a free and open society, individuals have the right to their side and to express their opinions without fear of consequences that limit their freedom.
Tyranny is obvious in the official suppression of belief because sanctioning sides requires a commissar, an office that has the authority to sanction dissidents. The commissar is the office with personnel who decides which side is a priori true or not and silence the side it deems false by fiat.
A priori involves denoting knowledge that proceeds from theoretical or ideological deduction rather than from observation or shared experience. Theoretical deduction presumes the validity of the theory in use, and in science all theories are open and subject to revision. The deduction used in the case of the commissar’s sanction flows from ideological presupposition, that is axioms or postulates derived from politics not from scientific reasoning. Therefore, the imposition of the deduction in such a case is the imposition of ideology, which is the central feature of totalitarian societies, from Soviet-style socialism to Nazi-style fascism.
Free and open societies liberate individuals from mandatory ideological systems, allowing them to choose or resist any ideological system. They are also free to choose or resist any theoretical system. The advancement of the heliocentric views of the social system, for example, depended fundamentally on dissent from the Ptolemaic system of geocentrism. Thankfully, even in the face of the commissar, dissidents persisted—but not without consequences.
The same is true with other controversial questions. For example, in the aggregate, blacks have a lower IQ than whites and Asians. In various literatures, this fact is chalked up to genetic inheritance, cultural inheritance, economic inheritance, etc (these are not mutually exclusive). To a priori rule out of order any argument positing genetic inheritance is an instantiation of tyranny. In a free and open society, a person has the right to consider and express the claim that there are distinct races and that grouped IQ differences are explicable on the basis of genetics.
One more example: grouped differences between men and women. Admitting wide variability and overlapping distributions, the means of a myriad of attributes deviate significantly. As a group, men are faster than women. They are stronger than women. They punch harder than women. They have greater lung capacity. They are taller. Moreover, there are differences in perception, reasoning, and temperament. One can say that, then, at swimming, for example, men are better than women. Another way of putting this is that men are superior in this domain. Inversely, women are inferior in this domain. To use the word “inferior” in this case will draw the charge of bigotry or prejudice. But, if it is true, the intent of the charge is to distract from the argument at hand by making it about the character of the arguer, not the substance of his argument. (It must be noted here that crossing over from prejudice to discrimination occurs when women are compelled to compete against men in sports.)
In all the examples used above, while people are certainly free to call people names, a free and open society tolerates the arguments the name callers seek to suppress, the truth of the claims arrived at through a rational examination of the available evidence. Yet we find ourselves in a situation where such rational examinations are suppressed or disallowed by various means—and these means undermine the foundation of a free and open society.

Some substances like purified sugar, cocaine or opiates hack human tastes and become (for some people at least) addictive. You can make all the arguments against them you want, but low agency people will be low agency. It makes sense therefore for the state to come in an control such substances for the common good.
What if there were false and damaging ideas that hack human imagination, should they be controlled by the state as well? Wouldn’t the trans fad, which sterilizes and mutilates children and vulnerable adults, be one of those ideas?