This framing of protest as "cancellation" in the context of supporting free speech is something I find perculiar. Surely protest is speech? If that is the case then if you support free speech you must logically support both the right to the original speech and the right of others to protest that speech.
When people say that people signed a letter denouncing the documentary without seeing it that's a little bit wide of the mark also. If free speech is a right that is to have any meaning whatsoever, it must certainly include the right to be wrong, not fully informed etc. If that's not the case, then speech can be shot down by saying the speaker doesn't have the right because they haven't done their research or the sources are inaccurate etc.
If I use my influential speech to get you to cancel a project or to have it removed from every major streaming service, am I merely exercising in free speech or also using social pressure to prevent you from speaking? The point here isn't that people are uninformed (that's bad, but obviously allows allowed) - it's that one group is demanding that something does not air and is claiming sole moral and cultural authority to do this. While it's their right to claim this, the consequences for everyone else are that they lose the ability to actually make the choices of which film they want to see on streaming services because another group has removed that ability. Why shouldn't the film air, and if it's terrible and awful beyond belief in every way, then the creators will forever have their names sullied? The reasoning here isn't even whether the film is good, but who the creator is, and not even because they've done anything bad really but because the single person the critics have focused on happens to be white.
You're making a completely false dichotomy. The complaint is not that people are just protesting the movie. It's that they're applying a lot of pressure on many parties to cancel the movie.
E.g. we're not talking about holding signs at the conference. We're talking about calling translators who worked on the movie, and telling them "denounce this film or we will make sure you never get another arab translation job again".
Not all speech is equivalent. Speech which is arranging a hit job is not protected free speech. Speech which is fraud is not free speech.
"I don't agree with this movie and I won't be watching it," is an expression of opinion and is completely fine with me.
"Withdraw the movie from the program and defund it," is a call for hostile action. Not as bad as "burn the director at stake", but still. I don't think it should be illegal to call for such measures, but it should be considered deeply shameful, on the level of advocating for slavery or torture.
You are doing the very thing you're criticizing here. Freedom of speech apparently includes making a movie, protesting that movie (both true) but not counter-protesting.
You've drawn that inference completely without support from what I wrote. I wholeheartedly support the movie, the protests about the movie and the protests about the protests about the movie. I don't agree with this categorization of protest as somehow different from the original expression in terms of free speech protection.
When people say that people signed a letter denouncing the documentary without seeing it that's a little bit wide of the mark also. If free speech is a right that is to have any meaning whatsoever, it must certainly include the right to be wrong, not fully informed etc. If that's not the case, then speech can be shot down by saying the speaker doesn't have the right because they haven't done their research or the sources are inaccurate etc.