Evidently, that idea was floated during the recent meeting between the Irish bishops and the pope.
From the BBC:
Two of the Vatican’s most senior officials have raised the issue of reducing the number of dioceses in Ireland.
The Bishop of Down and Connor, Dr Noel Treanor, told BBC Radio Ulster’s Sunday Sequence it came up at the summit on clerical sex abuse in Rome last week.
It was mentioned by Cardinals Giovanni Battista Re and Tarcisio Bertone.
Cardinal Bertone is Vatican secretary of state, while Cardinal Re is prefect of the Congregation for Bishops.
“It was mentioned I think by Cardinal Bertone and possibly by Cardinal Re as well, but the issue was not discussed,” Bishop Treanor said.
“It is an issue that is certainly ad rem (important) in terms of the long-term reform of church procedures in Ireland.”