I don't consume soy, it affects my hormones in a negative way. I don't think soy is inherently good or bad. I know it helps some women with hormone imbalances. But having no problems in that area, simply switching to soy milk caused mine to go out of whack. Like anything else, people need to eat it in moderation. I don't think people should eat it in huge amounts.
That sad, I personally find my flushes are more productive when I eat ZERO protien the day of the flush. Others have had success eating things like beans, which fill them up so they aren't starving in the evening, and have great flushes. So it is something you will have to experiment with.