I've bought the Hardline Premium package for xbox 360 but have now just bought an xbox One. Will the premium package transfer across or am I going to have to fork out another £40? I've seen theres a next-gen upgrade thing for Battlefield 4 (http://www.battlefield.com/uk/battlefield-4/next-gen-upgrade) but can't find anything about Hardline.
I've done some more digging on this so hopefully I'm allowed to answer my own question...
Owners of Battlefield™ Hardline Premium for Xbox 360 will also get Premium access on Xbox One.
and if I go to https://store.xbox.com/en-GB/Xbox-One/Dlc/Battlefield-Hardline-Premium/31f9628b-0142-420d-a94b-48d251a0c3b1 the price shows up as £0.00 rather than £39.99 so it looks premium will transfer.
I'm still waiting for the XBox and Hardline to arrive so I'll try and remember to update this with a definite answer when I get it.
Based on this Battlefield Forum Post it would seem like the Hardline Premium Package will not transfer across from your Xbox 360 to your Xbox One.