Like I said...
Why do you think it is that no-one has rushed to pick up the STN and DUB routes? Could it be... because nobody thinks they are viable...???
Most aviation execs know that if you let a route stagnate for more than a few days, it is very, very hard to get it going again. In these times, few are willing to spend the time on a route that may or may not make money.
I suspect Go have too many of their own problems to try NCL-STN, especially with such a good rail link. Who knows, though...