Credit to Amazon reviewer Sam_One, who noticed "something weird" going on back in May:
Something weird seems to be going on with Warner Bros. pre-orders. Loads of them are not available anymore, and all of them were removed pretty much at the same time (I had several of them in my "Saved for Later" list. This includes most releases of 300: Rise of an Empire, The Nutty Professor Box Set, The Man who knew too little, Looney Tunes Platinum Collection Vol. 3 etc. etc. All of them Warner releases, some of them pretty big.
Today, the Times confirms that Amazon has stopped accepting pre-orders for Warner movies, including The Lego Movie. (You can still buy Disney's Frozen, so your children won't actually die, at least not quite yet.)
What we have now is a race! Sort of: Amazon will keep strong-arming progressively more visible companies (Bonnier, Hachette, Warner); with each fight, more and more people will have to consider the power that Amazon wields, and the industries it can profoundly damage if it so chooses. Will the public turn on Amazon before Amazon crushes or cows all of its most important partners and becomes an actual multi-industry monopoly? Will bad press eventually overshadow consumers' ability to one-click drunk-order toilet paper and have it arrive the next day?
Ha ha, no, of course not, but you never know: Maybe some politician or regulator with a spouse in the entertainment business will find a new cause this year.