* Ancient Macedonians spoke an ancient Greek dialect. It was distinct from Attic Greek, the dialect of Athens, but still part of the wider Greek language family.
* Irish is a Celtic language. It's completely unrelated to Greek.
There is no historical evidence or linguistic connection that would suggest Macedonians ever spoke with Irish accents.
It's possible you might be thinking of a fictional representation, a humorous anecdote, or a misunderstanding of some historical detail.