FR can sweat their fleet relatively easily and not spend any cash on new planes at the end of their current order book.
Given the average age of their fleet is 3 years V Southwest 14 years then Ryanair can take a decision when their current orders are fulfilled to stop buying for 7 years and still be under the Southwest age.
Its easy for people to assume Airbus / Boeing would just ignore this BUT I reckon the replacements of the current management may see it differently.