Jewelcrafting neck items have more than one possible outcome when you make them; but you cannot choose what it will be… the one you got was ONE variant of many so you may want to stock up on gems to be able to make more to get a better stat. combination.
The version in BiS CAN be made in the game, you just have to take the chance that you will get that one. What helps is that if you make more than one of them, you can then choose which one is best for your way of playing & ‘obliterate’ (in the Obliterum Forge) the others to make Obliterum to upgrade the one you have to make it even better (the 8/8 part, in the item details).
AMR hasn’t got it wrong… it just knows that the BiS option CAN be made & is letting you know which one you need to aim for.