I usually write similar comments. I put a big line through all the options, big capital writing saying STILL IRISH or some other variation. I also point out that the letter usually takes 7 days to get to us. I was born in Australia but otherwise Irish.
To answer your question, No, I didnt get a letter like that, but I wish they would send me one. Maybe with the next letter I will attach a copy of my passport.
According to this, they will only accept original documents or a copy certified by a local garda or social welfare officer.
As if I'd send them my original passport! Can you imagine? It only took them six months from my initial application to determine I was eligible for child benefit - never mind that I had been living and working legally in Ireland for nearly nine years at that stage. I can just imagine them saying, "If you're really Irish, why do you want to leave?"