"About last night (A Haiku)" gets more attention where it is, therefore it should be left alone. On the other hand, I still think that "The Art and things we've made thread" should be moved to the Art section and possibly pinned.
Splendid to see you here again Waski_the_Squirrel. I thought of you relatively recently.
As for this issue, assuming you're teaching at a public school I think you have good reason to be steamed. The valedictorian speech as described sounds like a bit more than ceremonial deism. You may have seen the news about the valedictorian who was prevented from wearing a sash that had the US flag and the Mexican flag because a valedictorian speech "qualifies as school-sponsored speech, at least for the duration of the ceremony." Of course it is up to the school administration how they would approach the question. Since the speech has already been given, not sure what could be done aside from laying down some guidelines on future valedictorian speeches.