No idea, I think it still does. I doubt kids are being indoctrinated by it, its a ritual like lighting incense, we remember the ritual but not why or the context. Only now when people complain about it do I realize it had no effect on my patriotism. I didn't learn what a republic was for most of the years. What does one nation under god mean? No idea still.

Depends on school, district, grade level, etc. If I walked into any school in the country and saw it not/occurring, I would not be surprised or perturbed at all. It's just kinda part of life.

Think how Japan does calisthenics before work/school every morning. Not everyone does it, but enough do that it's kinda just part of Japan.