Right now EK has a lot of work to with the retirement of A332, A343, A345 and B772. A lot of changes but not so much new / additional routes.
HEL should be one of their next destinations in Europe. In the US there might be better options than DTW like PHL, MIA, DEN. Kathmandu was served in the past, flydubai flies there from DXB. Mexico-City flights right now are not possible nonstop. Due to altitude and runway length MEX-DXB need to stop somewhere which is time consuming and costs some money. B77X should do it nonstop once EK receives this aircraft from 2020 onwards.
Also interesting to see how EK will launch new routes in the future as the B77L (266 seats) will be their "smallest" aircraft in a few years. They just have 10 of them which are used for their long-haul flights.