Agree with the above post, AA won't come back as Primera is a LCC and majority economy, where as EOS etc were going to tap into AA's biggest money spinner. AA also seem to be reducing their JFK ops significantly.
Norwegian is probably the airline that will watch Primera most. I imagine IAG will also be watching closely in a different way with their A321LR on order.
Primera will go down well at STN I think, their schedule and aircraft size seems just right. Hopefully will open some more doors for long haul at STN.
Also, Thomson/TUI long haul has come to a end as of yesterday.