Route closures and diplomacy.
Ever notice that when an airline close a route they often use shortage of aircraft as a diplomatic excuse. eg CSA and Malev needed the ORK plane for extra sectors to Moscow as if closing the ORk route was the only option, There is nothing stopping RE from using an ATR 72 on ORK DUB if they wanted to. In fact the pressure from Ryanair has eased considerably in recent times so why close the route?