BCN will not support two airlines. The spotters may be happy seeing the grey and yellow brigade in town but all that will happen is that yields would become trash and the route would be at risk. This will put LOCAL jobs at risk if the other operator closes the route or worse, its NCL base.
Orlando is covered already. No way would a thrice weekly very seasonal service work from NCL.
Again Norwegian if any base ie significant non-based operation were to occur the locally based carriers would be harmed and when DY go bust NCL will be left with nothing.
I think people need to ask themselves what and why when they come up with suggestions. What the new airline would bring to a route and why they should do it. If it is to bring lower fares then that is no good for the longevity of a route or airline operation. Look at Murcia. It was flown perhaps 4/5 times a week between two airlines. Now look at it.
Please don't anyone mention the N word!