The DoT have had THREE YEARS to find cause to reject this proposal, they have had the best lawyers money can buy and the advice that came back is that the application is lawful and meets the requirement under open skies for grant of traffic rights.
Trump may of course overturn the ruling but I think thats very unlikely, even if he did so, then you are back to arbitration and simply saying no without just cause will simply result in the EU taking retaliatory action.
This result is so Brexit like, with people who have campaigned strongly for their position being unable to accept a verdict that does not accord with their position.
Trump will see this dispute for what it, protectionism, to protect a cosy club of mainly American airlines and a few inefficient European ones (AF/KLM, SAS & Lufthansa) wanting to maintain high prices across the pond as a money tree to prop up their loss making European short haul operations, Interestingly IAG supports the application as do many airports and regions in the US that benefit from inward tourism.
Norwegian probably need to move further with its employment methods and based on the changes to SH i suspect they will.
With oil prices on the rise again the economics of the 787 will get stronger with $ increase, by this time next year there will be dozens of flight a week from the US East coast to the west coast of Europe on the MAX in and out of smaller regional airports.
I would expect to see a raft of route announcement before Xmas