The moving bricks thing was always blue sky, folks. I can't see how they could possibly make it work with the amount of people going in and out all day. Like someone else said, it's a safety hazard and just not worth it to appease a few die hards.
Some of you might have your expectations way too high, Diagon Alley is going to instantly become the new gold standard in theming once it opens yet some people are complaining that the entrance doesn't have magically moving bricks or the extended queue in Gringotts isn't themed. Enjoy the beauty and glory of this, because it is taking theme parks to a new level.