In that case why do the IAA continue to provide an AOC to the company? I'm sure if what Ryanair are doing was illegal under EU rules, the IAA would tell them to change their employment policy or withdraw their AOC.
I'm not sure this issue falls within the jurisdiction of an XAA. It has nothing to do with EASA regs etc. nor, directly, with the financial well-being of the company. An XAA used to have an oversight of the well being to protect the pax from being dumped by a dodgy carrier going bust every week. One could argue these practices boost a carrier's potential to stay alive. I would have thought the local government's tax office would have jurisdiction.
I'm not following Agri B's thinking that things could be worse if this issue was addressed by the authorities. Surely if it was found to be non-koshewr the resulting change would be under the spot light by everyone; public, employees, media etc.