Did you read the article?
Prior to that, in 1972, the Irish hierarchy willingly embraced the repeal of Article 44 of the nation’s constitution, which acknowledged “the Holy, Catholic, Apostolic, and Roman Church as the guardian of the Faith professed by the great majority of citizens.” While that wording was not strong enough for Father Denis Fahey, I doubt that the great Apostle of Christ the King would approve of its removal, which is what 84% of Ireland’s populace voted for in a 1972 referendum.
This dismantling of Ireland’s constitutional recognition of the Church would seem to have resulted from two things, first, Pope Paul VI’s policy of weakening the historical ties between Church and State in such places as Colombia, Spain, and the Swiss Cantons of Ticino and Valais, all in keeping with the novel doctrine of Dignitatis Humanae.
So they were voting in secularism long before the EU. I think that reflects a broader problem than Church doctrine.
In that instance it was probably an ill-advised move towards peace with the North. We’ll quit being officially Catholic and then you will talk to us.