Getting the RYR pilots to join a union is only the very first step on a very long road. MOL will do his utmost to continue in the way he runs things now, no unions, ever.
He will simply refuse to recognise any union in the first instance. In a few years, after several Law Court appearances by both sides, he might be forced to concede that the pilots have a right to a union to represent them. He will simply close bases one by one, telling the pilots that they can have their jobs back when they sign up to his All New AirLine Ryaniar Aviation Pilots' Executive who can negotiate all they like.
Dream on if you think union membership is the panacea it appeared to be for easyJet and others!
Sorry to be so pessimistic but I am a realist.