I don't get it.
Aer Lingus contract Astraeus to host some of its aircraft on its AOC for a short period while it applies for its own UK AOC.
Aer Lingus pilots operate the aircraft on AEU's AOC. AEU get paid for "hosting". No Aer Lingus pilots lose their jobs. AEU hire some airbus pilots for their own newly acquired A320.
Aerlingus give notice of " early" termination. AEU get paid for the contract. No Aer lingus pilots lose their jobs. No Aeu pilots lose their jobs. The Irish Pilots Union get their way.
Maybe I'm missing something but this looks like a win / win for everyone. (Might have cost Aer Lingus a few quid for the experiment, but I bet AEU rates were "competitive" )
Maybe I'm missing the emotional involvment