That's almost definitely not true GG. I only preordered on Saturday from elsewhere, and that message was there then. I don't believe it has come into stock on Sunday and sold out by Monday. Maybe there is a supply train dispute. Like I said though Amazon UK probably accounts for 1% of a smaller market compared to the 10% or so of the much bigger US market. It is in no charts or movers and shakers. I got the same pre-order bonuses from elsewhere, which I think might be the problem. Maybe they asked for Amazon exclusive content, realised everybody else had got that content and refused to sell it. I have no answer. Maybe it will come out in gaming news somewhere about the reasons why.
Amazon are known for being petty, they often keep away from things viewed as rival products, which is why you won't find things like YouTube or google play games on your kindle tablet. It is what worries me when I see Amazon has no rival stateside, they can dictate everything at RRP, Whereas in the UK everyone competes, so I can buy an Xbox X with 5 games and extra controller for the same price as standalone X from Amazon, as an off the top of my head example.