As I recall MOL cited the 3 airports LHR, CDG and FRA as no go areas. I never recall AMS being mentioned, that said some things are changing, example, there are repeated mention from various media sources about feeder services to large carriers, that could play a part. Equally, an event like Transavia ops to Dublin from Paris primary airport combined with the continued desire to put it up to Aer Lingus. These sort of things give motivation.
EasyJet seem to be on Ryanair 's radar more than ever..
And they've been stranger to turning up at easyJet's bases (past and present ones), examples include Rome FCO, Madrid, Lisbon and now Amsterdam and Malfeasance... A distinct increase in competitive challenge to easyJet is a feature... Hence part of the interest in some of these airports...