Not necessarily: in the Diocese of Wichita and Mid-America (Antiochian) we have Fr. Paul Callahagan (not celibate) and Fr. Daniel Griffith (not Irish, but Welsh, and celibate--my own parish priest).
Celts sometimes reach way back to their roots when trying to follow Christ, and end up Orthodox. (The Irish Russian Orthodox priest could have just changed rites and stayed in communion with Rome if celibacy were the only issue. It was probably something like the filioque, or the fluidity of Latin canon law, or an objection to Barlaamite tendancies in the Latin church that pushed him Eastward.)
Ah, no where in his post did he say that the Irish surnamed Priest was a former Catholic. In this country he could have been a former buddhist or his parents could have been a mixed marriad.
Your assumption and subsequent diatribe reveals the extent of your bigotry.