In a nominal sense this is true because people fairly rarely renounce their religious identity, qualitatively it's almost certainly not the case. On paper 84% of the Irish population are still Christian, de facto the country is much more secular than it was decades ago resulting in legalization of abortion, gay marriage, removal of blasphemy laws, the world's fifth gay head of state etc.

Secularization within formally religious groups is progressing much faster than change in demographics.