To me it suggests that Skavsta and Rygge haven't given Ryanair the highest yields and that the priorities lie with beefing up Stansted and setting up bases in primary airports.
That would suggest a major shift in business model.The bullying of "in the middle of nowhere' airports to seduce them into believing they have a greater status than reality might be over. Will they be able to extract the same 'fire-sale' deal from the primary airports? If not will their pricing structure be viable?
Compare the airlines to the supermarkets. Lidl & Aldi are doing well, but they are in cheaper locations. If they move into the city centre they will reduce profits and have to cross subsidise from their out of town places. Will RYR do that or will they demand a certain profit from all their routes?