But even the most far out ideal of free speech DO NOT require private party to endorse and repeat your own opinion or speech. This is why free speech , freedom of expression , libertÃ© d'expression and such like are always about governmental restriction. You and me and any other have no right to force other private party to carry our speech or get it heard. I repeat, the church, Dawkins, me aepervius or you nemyst have a right to express ourselves without governmental interference, but we have no right whatsoever to force a 3rd private party to carry our speech.
This is essentially why this is not a free speech issue no matter what you look at it. Private party may at any moment, or any time, chose what they publish or show (usually this become a bit more complicated when you look at communication lines and common carrier rule, but here with cinema it is clear cut).