There is no need for a PSO route between Cork and Dublin. There was 11 flights a day on this route between 2 airlines in the 2000's. Obviously the hourly train service and the new motorway took away some of the passengers. However for connecting transatlantic passengers through Dublin, the last thing they want to do is hop on a coach to Cork with the jet lag.
Using DUB with the CBP is far better for travelers to the US rather than LHR or AMS.
Having travelled often between Belfast and Cork by plane in the past, I do it by train in more recent times via LUAS in Dublin. It's a real shame there isn't a rail stop at DUB.
Im sure Emerald would do it if they new it was viable. I cant see happening myself. The bus routes and motorway make it quick. The multiple daily flights to LHR & AMS provide alternative stopovers as well.
There would be faster connection times there. ‘So people arent waiting around jetlagged’
In other news Aer lingus will swap a 320 for a 320 neo in Cork from 8 Nov to operate ORK/SNN -LHR. The ORK crew operate SNN LHR in the winter