re: Uh, gb
Had rabbi chosen not to include a prayer, it would have meant the case would not have even been heard by Supreme Court. No govt institution was requiring any kind of prayer. The institution may have expected and wished for some type of prayer, but there was no specific kind of requirement of the content of the prayer.
Therefore, the issue is what the rabbi chooses to say.
And probably a large part of what kind prayer that would have been given, would depended upon the rabbi's judgment of what would be most acceptable and meaningful to the audience he was addressing.
And the idea that anyone can address any audience in which everyone agrees and feel happy about the content of a speech is utterly foolish.