Regardless of whose speech was being curtailed at Dover, it was not a First Ammendment (free speech) issue. It would not have been a free speech issue if the decision had gone the other way, and the teachers had been ordered to say something they didn’t believe.
The Dover case never involved freedom of speech.
A Judge, a federal judge, non-elected, having NO authority to represent the community in such a issue, ruled not only that the school board may not speak a certain thing -- speech by label on a book -- but ordered that we we speak of science or teach of science that only the orthodoxy of the modern Darwinism be taught and spoke of. The Judge overstepped, and stole rightful authority. He stole not only "free speech" rights, but many others.