Is it a case of the aircraft being registered abroad for financial reasons or operating through an overseas subsidiary?
The former is very common. Many years ago spotting at ZRH I saw a Swissair 747 with an N rather than HB registration, doubtless owned by an American financial institution. The operations would have been no different to an HB registered aircraft, although as a previous post has mentioned the US authorities would have a regulatory interest.
Obviously if they are to be operated by an Irish based subsidiary that would be a further step, but it is not clear that this is to be the case.