It's a premmium product, it says right there in the article, why the Hell are people debating if it's going to be $400? It's going to be $500, the Xbone launched at that price. And no, even if it's a year later than the PS4 Pro, it will have a a 4K BD player which also raises the price.
The word "Premium" doesn't really mean anything. People used that word to support the idea that the PS4 Pro would be beyond $399, and look what happened. All that matters is that it's more expensive than XBO.