I repeat my earlier comment. There is no barrier in the bilateral to any carrier of either side launching more transatlantic services from MAN. Waste all the time you want on this hypothesis but it’s not the case.
So if the airlines aren’t coming l, but have the equipment to launch other routes in the meantime, MAN has not made it to the top of their list of things to do with the assets they have. That will change over time - even if some of the things they are doing don’t work as expected, which could be the case with the pile-on of capacity into Nice, Naples or even Edinburgh.