I really cannot see why it couldn't work
It's marginal, Newcastle is not a capital city like Edinburgh nor a large inbound tourist gateway for the the Highlands and Islands like Glasgow. It's an English regional city and given United's Belfast route is hanging by a thread and Bristol was dropped, I don't see United giving it a go. American are phasing out the B757 and USAirways are now part of AA, which leaves Delta who had two goes at EDI and failed. Since BA are not going to be an option and Emirates have many more high yielding options going West from Europe, there's is no likely contender aside from Jet2 doing seasonal IT type ventures while they still have B757s. Virgin don't operate anything small enough and are focussed on maxing out the JV at LHR with Delta.
Going forward NCL are even more likely to be squeezed by an increasingly aggressive EDI, especially if with QR and EY moving in, Emirates decide they don't want to be left out of a rich European capital city. Look how fast EK moved for a third daily MAN to drive QR back to less than twice daily, it's a firefight.
Also given BHX lacks any F offering, I doubt NCL would be in the running? QR don't offer F from EDI nor will EY, the oddball here is EK offering F from GLA (!)