If they were to expand,
They have the planes on order to expand. They control the size of the fleet by selling planes. Last year that was very profitable making over 2 million euros more than book price for each plane. Ryanair have some very good profitable routes but finding new routes that would be profitable is going to be hard. Ryanair are going to have more planes then they will know what to do with. Airports will also have a stronger hand as Ryanair need more routes and have parked planes.
Ryanair are also upsetting lots of PAX who have already booked for flights that have been canned. I think it is the start if a downward sprial.