Any attempts to limit freedom of speech by labeling it as disinformation, misinformation, hate speech, or any other label, relies on someone's opinion. That opinion may be biased, subject to political or ideological controls, or simply wrong. Each individual must be able to judge for themselves the truth, falsity, value, or interest of speech, and to interpret it as they see fit.
Freedom of speech simply means that anyone is free to say whatever they wish in whatever medium will accept that speech to whatever audience will listen. It does not require any medium to carry that speech, nor any audience to listen. It does not require the content of the speech to be true, palatable, inoffensive, accurate, in any particular language, or even coherent. Any prospective listener can decide for themselves if they wish to listen or not.
The function of free speech in a Republic is to ensure that all viewpoints, opinions, ideas, and policies get fair hearing and can be discussed openly to arrive at a best result. If there is any bias, any censorship, any attempt to restrict discussion to "acceptable" directions or policies, the results of such discussions will no longer reflect the consensus of the population, and will leave significant portions disaffected, angry, and potentially seeking other means to be heard.
Freedom of speech does not mean that listeners must agree with the speaker or accept his views or positions. It simply means that each person must be able to contribute to the discussion. People are free to listen, hear the arguments, and still disagree.