I have asked both ShopTo and Amazon customer service directly whether the Black Ops 3 - Xbox One version came with the NUK3TOWN bonus map code. Both replied with a resounding NO. I do not have the amazon transcript to hand, but here is ShopTo reply: https://i.gyazo.com/6e729b050549d3d269e07e383fc6fe71.png
With GAME claiming exclusivity "Black Ops 3 NUK3TOWN Edition - Only at GAME" GAME - Lock and load with the Call of Duty: Black Ops 3... | Facebook
There does not seem to be a clear answer. Retailers saying no, with no mention of "N3KETOWN" once in the product description, and GAME claiming the only one to offer it. Yet the forums here are claiming it for every pre-order.
USA Retailers on the other hand are all listing the Nuketown bonus map. Compare UK vs US Amazon.
UK: Call of Duty: Black Ops III (Xbox One): Amazon.co.uk: PC & Video Games
People link to this: Activision Support
Which is connected to the USA version of your website. I have yet to see anywhere that says specifically that ALL UK pre-orders come with NUK3TOWN bonus map outside of Forums. Retailers are saying no.